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TRAFFIC MANAGEMENT & ACCIDENT INVESTIGATION
By:
PROF. OSCAR GATCHALIAN SORIANO, LC
BSCrim, MSBA, MACrim, PhDCrim
===================================================
History of Transportation
The history of transportation can be conveniently--if over-simply--divided into period during which
motive power was most characteristically furnished
by human and animal muscle, by such natural forces
as wind and gravity, and by fuel-operated machines.
1. Manpower
Stone Age mans transportation of firewood and
of animals killed in the hunt probably led to the
invention of the sled. From the sled early man mayhave got the idea for ski pieces of smooth board
resembling sled runners but worn on the feet of the
hunterand later of snowshoes. The first
watercraft, the man-powered raft and canoe,
probably evolved from the floating log.
The greatest advance in land transport after
the sled was the wheel, probably first invented in
the Tigris-Euphrates Valley sometime before 3500BC. The ancient Egyptians took little or no part
in the invention. The great blocks of stone that
went to make the pyramids were floated on barges
down the Nile River and then moved over land on
sleds running on rollers. Gangs of slaves dragged
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the blocks of stone by means of large ropes, while
other slaves at the rear of sled picked-up the
rollers over which the sled had passed and hurriedaround and place them at the front. To raise the
blocks of stone to their positions in the pyramids,
the Egyptian built ramps.
2. Animal Power
But while human muscle power was still in
widespread use for transport in ancient Egypt,
animal muscle power was being widely exploited in
the other river valley civilizations. The ox, theass, and the camel were tamed somewhere in the
Middle East by 3000 BC. In arctic snows the
reindeer, which can carry a load of about 130 lbs.
(60 kg.) without much effort, is still widely used.
In the higher altitudes of the Himalayas the yak, a
species of ox, is used as pack animal. In India
the beast of burden is often the elephant. In Peru
the llama is domesticated and used as pack animal.
The horse was tamed somewhere in its native
habitat on the steppes of Central Asia. The
invention of the bit and bridle before 3000 BC gave
steppe folk control of the horse for riding. The
stirrup was not invented until Roman times,
probably somewhere in Western Asia. The earliest
known stirrups have been found in South Russia in
tombs dating from between 100 BC and 400 AD.
Until the invention of horse collar, about 900AD, horses were harnessed like oxen. A yoke
passed over the withers, and a strap tightened on
the horses chest when it pulled, half strangling
the animal. The Romans, knowing little anatomy,
did not realize that a good harness for the ox was
a very poor harness for the horse. This fact
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explains why the horse was little used as a draft
animal until late in the middle ages, whereas the
ox almost universally used as draft animal from3000 BC. Where the horse was used for
transportation during the middle ages, it was
mainly as a pack carrier at its sides.
Another invention that played a great part in
the history of transportation was the horseshoe.
In its wild state the horse can gallop for long-
distance on soft grass of the Asiatic steppes. But
if it is driven on a hard, metal road its soft
hoofs soon become broken and it goes lame. An ironhorseshoe, mailed around the edge of the hard hoof,
stops the hoof from breaking away. It appears that
the iron horseshoe was invented in Gaul about the
time of Julius Caesar, and taken to Britain soon
afterward.
3. Wind Power
Primitive man may have hoisted crude sails of
skins on his rafts of canoes, for there is clear
evidence of the migration of peoples over wide
stretches of ocean long before 3000 BC. The ships
of Egypt, Phoenix, and Greece were driven partly by
a large square sail of mid ships and partly by
oars. The war gallery, in which a greater degree of
maneuverability was needed, had narrower lines and
depended more on oars than did the trading vessels.
In other parts of the world the original dugoutcanoe developed into different kinds of watercraft.
In the North Sea a ship that was sharp at both
ends, like canoe, developed, where as the
Mediterranean type of vessel had a rounded stern.
In the Pacific, through rafts remained in the use
in some regions, a completely different type of
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ocean-going watercraft, the outrigger canoe,
developed. In Chinese waters at junk appeared.
Mediterranean ships were all carvel built, that
is, the planks were placed side by side like the
boards on a floor, and the cracks between the
boards made watertight with tar. The ships of the
North Sea, however, were made of overlapping
planks, or clinker built. North Sea ships had only
one steering oar, placed on the steer board, or
starboard, quarter, whereas the Mediterranean ships
had two steering oars one on each side of the
stern. The rudder that is used for steering inmodern ships did not make its appearance until
about 1200 A.D.
A great aid to sea transportation reached
Europe about 1300 AD in the form of the ships
compass, a device first known among Chinese sailors
and then transmitted by the Arabs. An important
improvement in ship-building took place about 1450
AD with the development of the three-master ship.
Thereafter the story of sea transportation is
largely the story of the conquest of the whole
globe by the three-mastered skin.
4. Roads and Vehicles
The Romans brought road building to its highest
point of perfection in ancient times. The Roman
road network reached a total of about 50,000 mi.
(80,000 km.), with feeder roads branching outfrom the main highways. The roads were costly
because Roman road engineers assumed that deep
foundations, formed by layer after of heavy stones
were necessary to make roads that would carry heavy
traffic for many years. This theory was not
completely abandoned until John L. Mc Adam
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perfected the macadamized road in England about
1815. Realizing that dry native soil would support
any weight. Mc Adam made the surface of his roadscompletely watertight and curved so that main would
run off them as off a roof. He did this pounding
and rolling a layer of small stones into a hard
surface. This road remained the best that could be
devised until the rubber tires of the last country.
Significant improvement of road vehicle began
with the adoption of coach spring about 1650. In
the mid 18th century English roads were so bad that
coaches could average only about 4 mph (6.4 km/h),and the mail was usually carried by boys on horses
for delivering the mail. The first mail coach run
in March 1785 and by 1800 the English mail coach
system was in full swing.
Canals, railways, and steamboats. The
improvement in roads, in the horses and in coaches
had solved the problem of fast transportation of
passengers and light freight, but there still
remained the problem of heavy transportation. This
problem was met first by the development of canals
and later by railroads.
In 1761, the Duke of Bridgewater arranged with
an engineer, Jones Brindley, to Manchester, 7 mi.
(11 km) away. As a result the price of coal
dropped by half, while still allowing the Duke
plenty of profit on his investment. Brindleys
success led to England, in particular was coveredby a network of canals. The first American canal,
opened in 1825, connected Lake Erie with the Hudson
River at Albany.
English canals fell into decay with the coming
of the railroad. William Mardlock and Richard
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Trevthick had made early types of locomotives
before 1800. But it was George Stephenson who
pushed through the final stages of the fullydeveloped railway locomotive. Stephenson built his
first model in 1814 for use in hauling trucks of
coal. The first railroad was the Stockton and
Darlington Line, begun in 1825. The second, the
Liver Pool and Manchester, followed in 1829.
At first, it was certain that these early crude
locomotive should be more satisfactory than horses.
It was assumed that locomotives would not be able
to haul heavy loads up an incline, since thewheels, it was thought, would spin without gripping
the rails. This theory was later found to be false,
but only after long sections of English lines, at
great cost, had been made as near horizontal as
possible.
By 1840 the English railways had put nearly all
the main coaching companies out of business, and
the road ceased to be an important factor in inland
transportation until the automobile era began about
1900. In the USA, the Baltimore & Ohio Railroad
Company began work on the first American railroad
in 1828. Construction of Canadas first railroad,
the Champlain and St. Lawrence, began in 1832.
The development of the steamboat proceeded
simultaneously with the development of the steam
locomotive. Here the steam engine was to impart a
rotary motion to paddle wheels. The firstsuccessful steamboat journey in USA was made by
Robert Fultons Clermont up to the Hudson River in
1807. By 1811 the first steamboat appeared on the
Ohio River, inaugurating the great steam boating
era on the inland waterways.
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5. The Bicycle
The bicycle is important in the history of
transportation, not only in its own right, but
because of the part of bicycle industry played as a
nursery of automobile builders. One of ancestors of
the modern bicycle was the Hob Horse, or Dandy
Horse, which could be seen on the English
macadamized roads after 1818. The wheels of these
machines were of wood, with tires of iron, and the
riders pushed themselves along with their feet onthe ground. There was a steady improvement in the
bicycle throughout the 19th century, until the
safety bicycle, with pneumatic tires, at last
appeared. Some of the earliest automobiles ran on
four bicycle wheels.
7. The Automobile
In England for some times after 1800 it seemed
that the future of mechanical road transportation
with the steam carriage. Stem traction engines were
a familiar sight on many roads throughout the world
toward the end of the 19th century.
The future of mechanical road transport,
however, lay with vehicle driven by the internal
combustion engine, the invention of which usually
attributed to the Frenchman Etiene Lenoir. By 1865
there were 400 Lenoir gas engines in France doingsuch light work as cutting chaff and driving of the
modern automobile when he put toward the invention
of the modern automobile when he put one of this as
engines in a carriage and drove around his factory.
This carriage also made a journey of some miles to
Paris.
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Two German inventors, Nicolaus Otto and
Gottlieb Daimler, also pioneered the manufacture ofgas engines, and Daimler later became a successful
manufacturer of automobiles. At the same time a
small array of inventors was at work in various
countries on the development of early types of
automobiles. The invention of the pneumatic
bicycle tire by Scott, John Boyd Dunlop in 1988
gave a tremendous impetus to this early work.
8. Air Transport
Not until the development of the internal
combustion engine can the era of air transportation
be said to have begun. Men were making balloon and
flights, however, or more than a century before
Wilbur and Orville Wright made their famous first
flight at Kitty Hawk, North Carolina, USA, in 1903.
The progress of air transportation was hastened by
World Wars I and II. An important advances in
aircraft propulsion occurred with the invention of
the jet engine. Until this invention practically
every great advance in transportation techniques
had been the result of the application of the
principle of rotary motion.
The jet engine has made possible speeds that
could never had been attained by the rotary action
of the air-crew is effective only in the earths
atmosphere. The rocket, however is effective
beyond the earths atmosphere, and its developmenthas opened up the era of space exploration and
interplanetary travel.
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The Word Traffic
The word traffic originates from Greco-Roman
word Trafico with reference to the movement of
people that dates back from the dawns of history:
from the domesticated horse-drawn wheels to
horseless carriage. The Greek originally called
the system Trafriga after the early horse-drawn
chariots with spoked wheels.
If savants of Rome are to be believed, there is
no dispute that the word Trafico is a Greco-Romanword, but the word traffic was created from the
famous Trafalgar Square, the hub-center of
commerce and culture in the heart of London.
But in Latin, the word traffic is denominated as
Commercium with reference to the movement and
control of goods in transit from un-wheeled axle to
horseless carriage. This intellectual discourse of
discoveries only reinforced the universal dictum
that traffic refers to the movement of people and
goods and not vehicle. Perhaps this is the missing
jewels in the systematic strategies of traffic
management.
Legal Basis in the Traffic Management Process
1. Republic Act No. 4136, The Land
Transportation Code of the Philippines, asAmended.
2. Republic Act No. 7160, The Act Providing
for a Local Government Code of 1991.
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Definition of Traffic Management
Traffic Management presupposes an understanding
of the motivation behind the behavior of motorist,
commuters, and pedestrians. Any attempt to
redirect their behavior without understanding will
not be able to effectively solve the traffic
problems.
Innovative Policy to Address Traffic Problems
1. Reiterate the use of public roadways as a
matter of privilege and not as matter of right.
2. All forms of privatization of public
thoroughfares should be controlled.
3. Must encourage the development of a mass
transport system and de-emphasize the use of
private vehicles.
The Main Tasks Required to Improve Traffic
Management
1. Consolidate the single road use handbook,
all the traffic laws, rules and regulations,
guidelines, must be revised and issued yearly.
2. Ensure that each traffic user is trainedand disciplined.
3. Revalidate all drivers licenses and all
certificates of vehicle registration.
4. Clear the road network of obstructions.
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5. Streamlining the traffic adjudication
process.
6. Fast-track the shift to a mass transit
system.
7. Complete the basic framework of the road
network.
Causes of Traffic Congestion
1. Immediate
Congestion grows most obviously and at alarming
rate primarily in areas experiencing rapid
population growth, which cause parallel increase in
the ownership and u se of automotive vehicles.
2. Long-Term
Commuting during certain hours add considerably to
traffic congestion. The so-called rush-hours are
concentrated in relatively short period each day,
mainly from 7:00 to 9:00 in the morning and from
5:00 to 7:00 in the evening, when most people rush
to and from work.
Strategies in Resolving Traffic Congestion
1. Supply-Side Strategy
Expansion of the peak-hour carrying capacity of an
areas transportation system seems to be the most
intuitively obvious response to greater congestion
can be implemented through diverse means: 1)
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Building more roads or widening existing ones in
areas that have experienced rapid growth; and 2)
making transportation systems more efficient.
2. Demand Side
One of the demand-side tactics transportation
economist advocate is peak-hour pricing. This is
achieved by charging all drivers who use crowded
highways during peak-hours a toll large enough to
discourage many others from doing so.
Another demand-side strategy is shifting peak-hourtrips to other times of the day. This may be
achieved by staggering work hours among different
organizations, adopting flextime policies or even
four-day weeks. Changing week hours would slightly
more effective at reducing congestion in the
morning.
The 5Es of Traffic Management
The concepts of traffic although originated in
Egypt are being claimed by other countries. While
its sophistication and the principle of the 3Es
Enforcement, Engineering, and Education was
developed in Rome, there is however, no historical
impediment that the original traffic philosophy
began in Egypt.
By historical perspective, 3Es was dovetailedin Egypt, chiseled in Rome and upstaged in the
U.S., by time and event. It was an indispensable
ingredient in the traffic gems, mined from years
after years of event.
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At present time, it is a clinical autopsy on
traffic management to dissect and create new ideas
that can bury the corpse of 3Es concept to givebirth to the 4th E Environment, and the 5th E
Economics. Giving birth to the additional 2Es,
traffic management now a day deals with 5Es, i.e.,
enforcement, engineering, education, environment
and economics.
Definition of Traffic Enforcement
It is an action taken by the traffic lawenforcers and the count to compel obedience to
traffic laws and ordinances, regulating the
movement and use of motor vehicle for the purpose
of creating deterrence to unlawful behavior by all
potential violators.
The Five (5) Essential Steps of Traffic Enforcement
1. Detection
Wholly a traffic law enforcers responsibility
and entails in looking for the defects in the
behavior of motorist, pedestrians, vehicles,
equipment, and roadway condition. However, requires
knowledge of law on the part of the traffic law
enforcers.
2. Apprehension
Wholly a traffic law enforcers responsibility
where the traffic law enforcers are required to
take action at once to prevent continued and future
violations.
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3. Prosecution
While this is a court function the traffic law
enforcers also provides corresponding influence
through preparation and introduction of evidence or
by close contact with the prosecuting officer.
4. Adjudication
While this is obviously a court function, the
traffic law enforcers provides influence on thisstep by acting as witness to the prosecution or
supplying additional evidences, this step
determines the guilt or innocence of the
respondents.
5. Penalization
The court imposes the penalty upon the
respondents. The penalty is greatly influenced by
previous records of conviction as provided by the
traffic law enforcers.
Major Elements of Traffic Law Enforcement
Activities
1. Enforcement System
Consist of legislation, police and the courts.Legislation defines and specifies correct or
incorrect road user behavior. Traffic law
enforcers and the courts is charged with the
responsibility of insuring that these laws are
adhered to.
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2. Road User System
Includes pedestrians, pedal cyclist, drivers,
passengers and others.
3. Traffic System
Consist of the entire road and vehicle complex.
Kinds of Traffic Law Enforcers Action
1. Arrest
It is enforcement actions which consist of
taking person into custody for the purpose of
holding or detaining him to answer a charge of law
violation before a court. Arrest is made when the:
1) the offense committed is serious; 2) detention
is necessary to avoid continued violation; and 3)
there is reasonable doubt that the violator will
not appear in court.
2. Traffic Citation
A means of having violators appear in court,
without physical arrest. Kinds of which are: 1)
Traffic Citation Ticket; 2) Temporary Operators
Permit; 3) Traffic Warning.
An enforcement action which does not
contemplate possible assessment of penalty by the
court or otherwise as a results of warning alone.
It is of three (3) types: 1) visual; 2) verbal; and
3) written
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Definition of Traffic Supervision
It is defined as keeping informed on streets,
highways within existing regulations to make their
use safe and expeditious.
Definition of Traffic Control
The control of vehicles or pedestrian at a
certain point or area by mechanical means, fixedobjects or manpower.
Major Causes of Traffic Jams
1. Multiple Head-on Collisions
Statistics tell us that the impact of any head-
on collision on the highway is beyond comprehension
for flesh and debris littered on the roadways. An
even experienced investigator is sometimes shocked
at the gory sight of the tragedy and may cause his
investigation in snail pace. This undue delay is
an invitation to traffic jams.
2. Flooded Area
The cause may be attributed to clog drainage
network or engineering failure to consider theinterplay of ecology in road constructions.
3. Bridged Collapsed
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Rampaging flood due to heavy downpour may cause
soil erosion of the river bank and in the process
weak bridge foundation, collapsed.
4. Landslide
Denudation of the forest, causes to loosen the
earth surface and as a consequence of torrential
rains may cause the earth and boulders to fall or
landslide.
5. Overturned Fourty-Footer Van
When detach may go wayward or uncontrollable
and rest across the street, constricting of fully
block the road to traffic. Its removal can only be
effected by a ten-toner towing machine.
6. Logs Rolled from the Trailer Trucks
A freak accident but may precipitate at traffic
jam if strewn across the road for its removal
cannot be made manually but only either to heavy
crane or bulldozer.
7. Oil Leaks
From tanker that covers three to five kilometer
oil leaks on cemented pavement could create
pandemonium traffic accidents that would give rise
to suits and counter-suits.
Instant Solutions to Traffic Jams
1. One Way Traffic
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An important tool to decongest the traffic
standstill until such time that the density of the
vehicle is reduced to accommodate the regular flow.
2. Counter-Flow Traffic
A temporary scheme when the volume of one lane
direction is so saturated that the movement of the
vehicles is practically nil, while the flow of the
opposites direction is light in scale, the only
solution under the circumstances if to counter-
flow.
3. Re-Routing of Traffic
When the density of vehicles in opposite
directions has reached such proportion tantamount
to a complete halt of movement, the only
alternatives is to adapt the re-routing of traffic
to secondary streets.
4. Diverting of Traffic
When the magnitude of traffic conflicts was on
vast scales: flooded area, landslide, bridge
collapsed and other contingencies, the only
feasible solution is diversion of traffic. The
difference between re-routing and diverting of
traffic, the latter is large in scope, long and
tedious in perspective.
5. To Open Private Roads for Temporary Access
Most often than not, residents of exclusive
subdivisions vigorously opposed the use of their
roads under the many real or imaginary pretext.
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But the objection can be assailed under the police
power of the state.
6. Stop-and-Go Signal
One of the secrets to unlock the monstrous
traffic gridlock is for one lane to move. Unless
this can be affected the problem would be
aggravated by the passage of time. The scheme
should only be implemented when other alternativeis seemingly un-adaptable.
7. X-Option
When the situation is so grave that solutions
are nowhere in sight, traffic enforcers should
adapt the multi-options as the viable approach to
solve the traffic orgy.
Traffic Engineering
Forecasting of future traffic and evaluating
the magnitude of street hazards through traffic
engineering is not as simple as measuring the
height, length and width of the cube.
Taking the prevailing attitudes and atmosphere
of publics impatience towards the strange-shapedof geometrical road design is more than meet the
eye. Public attitude has turned corrosively
negative for they believed they were betrayed by
promises for safe travel. This is the unspoken
sentiment of the public in view of agonizing twists
and turns of events. But what is worse, if we hear
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no voices, except silent murmurs of the despised
citizenry.
To escape from frustrations and wants, traffic
engineering must know all and forestall all effects
whether natural or man-made calamities. A formula
that will dance to the tune of new technology, new
horizon and new vistas to open the floodgate of
traffic engineering in contemporary times.
Definition of Traffic Engineering
Traffic Engineering is the science of:
1. Measuring traffic and travel.
2. The study of basic laws relative to the
traffic law and generations.
3. The application of this knowledge to the
professional practice of planning, deciding, and
operating traffic system to achieve safe and
efficient transportation and goods.
Geometric Design
A traffic engineering phraseology for
forecasting future traffic demand on target year
for road design. It is indicator dictated by
development of land use, industry, economy, andpopulation component.
Many countries vary on the target year for road
design on account of topography, development,
environment, cultural idiosyncrasies and road
factors. From the viewpoint of traffic
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engineering, the maximum life for road design is
within the range of 15 to 25 years, and the
prevailing range now is 20 years.
The geometric design of road in order to have a
reliable forecast for viable projection of traffic
demand is determined by traffic generators, among
others: developmental plan, economic index, zoning
schemes, land use and population growth.
The hourly, daily and annual volume of traffic
is graphically taken into consideration for road
designs. Corollary, to maximize safe and speed,the physical features of the highway is considered
in the formulation of the design speed to determine
road design and safety factors.
Functions of Traffic Engineering
1. Fact finding, surveys and recommendations
of traffic rules and regulations.
2. Supervisions and maintenance to the
application of traffic control devices.
3. Planning of traffic regulations.
Road Check Objectives
The objectives of road check are to detect andinspect the following:
1. Faulty vehicle equipment.
2. Registration and licensing of violations.
3. Intoxicated drivers.
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4. The load or cargo of commercial
transportation vehicle for load weight.
Considerations Taken When Conducting Road Checks
1. Minimum delay to motorist.
2. Thorough checking procedure.
3. Protection, safety of both motorists andpolice officers.
4. Timing, location and frequency.
Kinds of Traffic Control Devices
1. Traffic Signals
2. Road Signs
3. Road Markings
Functional Classification of Traffic Control
Devices
1. Regulatory Devices
It is having an authority of the law and impose
precise requirement upon the action of the road
user.
2. Warning Devices
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Are used to inform the road user of potentially
hazardous roadway conditions or unusual traffic
movements which are not readily apparent to passingtraffic.
3. Guiding Devices
Are employed simply to inform the road user of
route, destination, and other pertinent
information.
Primordial Purpose of Signal Control
1. To minimize traffic conflicts and time
delay.
2. To reduce vehicular accident.
3. To economize manpower.
Classes of Traffic Signs
1. Danger Warning Signs
These signs are intended to warn road users of
danger that lies ahead of its nature.
2. Regulatory Signs
These are intended to warn road users of
special obligations, restrictions or prohibition
with which they must comply. It is subdivided into
three categories:
1) Priority Signs
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These are signs intended to regulate
priority over a particular road section or roadwayintersection.
2) Prohibitory or Restrictive Signs
These signs can be used on specified
section of the road which will be easily seen by
motorist to indicate regulation which is
prohibitive or restrictive in nature.
3) Mandatory Signs
These signs are intended to guide road
users of special rules in which they must comply
for the safety, convenience and smooth flow of
traffic.
3. Informative Signs
These signs are intended to guide road users
while traveling, and are subdivided into:
1) Advance Signs
These are the names and distances of the
principal destination or destination served by the
intersecting roads.
2) Direction Signs
Unlike the advance direction signs, direction
signs shall be placed at the right of intersection
to show the direction and destination of a route.
Direction signs are different from mandatory signs,
since these signs gave only information as to
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direction and destination of place, while mandatory
signs require compliance.
3) Place Identification Signs
These may be used to show the frontier between
two countries or for the purpose of showing the
beginning and/or end of built-up areas.
4) Confirmatory Signs
These are used to confirm the direction of a
road. They shall bear the names of one or more
places. Where distances are shown, the figures
expressing them shall be placed after the name of
the locality.
5) Other signs providing useful information
to guide drivers.
6) Other signs indicating facilities for road
users.
Road Classifications
1. According to Political Subdivision
1) National Roads
The main road as conduit system with a
right of way from 20 meters to 120 meters.
2) Provincial roads
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The linkages between two municipalities
with right of way from 15 meters to 60 meters.
3) City Roads
The inter-link between municipalities and
within city proper with right of way of 15 meters.
4) Municipal Roads
All roads within the town proper with
right of way of not less than 120 meters.
5) Barangay Roads
Commonly called farm to market road with
right of way of not less than 2 meters.
2. According to Functions
1) Feeder Roads
Intended for farm-to-market roads.
2) Local Collector Roads
Intended to collect traffic from feeder
road to municipal road.
3) Major Collector Roads
Intended as major arteries to collect
inter-locality traffic to provincial road.
4) Major Highway
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Serves as main artery that caters on big
volumes of vehicular traffic on national roadway.
5) Expressway
A through traffic for free-flow of
vehicular movement.
6) Tunnel Road
A passage of wide section cut through a
hill or sea to shorten circuitous roadway.
7) Subway
An underground conduct running entirely
under the ground for fast travel route of
commuters.
8) Skyway
A modern urban system of roadway above
street level for free-flow traffic.
3. According to Topographical Terrain
1) Flat Road
2) Zigzag Road
3) Steep-Hill Climbing Road
4) Down-Hill Road
5) Winding Road
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6) Mountainous Road
7) Roller Coaster Road
Boulevards and Avenues Distinguished
Many are in the quandary as to the whale of
difference between avenue and boulevard.
There is an international acceptance that they
are both national roads. Both are broadthoroughfares, but boulevard is more prestigious in
sophistication than an avenue. Often than not,
boulevard is teeming with grassplots and tress
along the center, the sidewalk and oftentimes,
boulevard is with lighted post in highly urban
centers of the world. It is for this reason that
the boulevard is named after great men and heroes.
Sidewalks
It is an integral part of the roadways in any
metropolitan cities of the worldit is also one of
the specie of geometric designs. Sidewalk is the
answer for the safety of pedestrian safety. Thus,
sidewalk reduced the hazards of pedestrian to the
slender yardstick of traffic engineering.
Intersections
Today, urban cities of the world walk on 2-legs
man and machine. But the continuity of its
locomotion depends upon the inter-link of
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connecting road network at intersection to meet
traffic demand.
The plan and design of intersection is based on
traffic component, traffic volume, speed, traffic
distribution, canalizations of traffic accidents
and future traffic demand.
Kinds of Intersections
1. Three-Leg Intersection
1) T-Type
2) Y-Type
2. Four-Leg Type
1) Right Angle
2) Oblique
3. Multi-Leg Intersection
4. Rotary Intersection
Fundamental Principles of Intersections
1. Intersection should be avoided on curve
section, bridge, attaching part, cutting, and
crest, near entrance of tunnel and besides railroad
crossing.
2. Intersection should not be greater than 4
legs. While 4-leg intersection is better than 3-
leg intersection, however, if 5-leg intersection is
unavoidable it must be used only as an exit.
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3. Two roads should not intersect as a small
angle. Intersecting at less than 60 degrees makes
it difficult for drivers to turn at acute angle andin effect constrict his visibility particularly 10-
wheeler trucks.
4. Distances between two intersections should
be based on land use of density of road network.
Factors that determine the minimum distance of two
intersectionsqueue length by the control of
traffic signals, length of weaving section, length
of turn and limit of drivers concentration.
Definition of Filter Lane
The word filter in its literal meaning is to
control or constrict the movement of vehicle as it
passes through the lane designated therefore. This
traffic engineering design is to prevent traffic
gridlock at the intersection when turning left at
the green arrow filter signal.
Channelization
A traffic engineering terminology that
separates or regulates the conflict of traffic
movements into a definite paths of travel by means
of traffic island or pavement markings for the safe
and orderly travels of both man and machine.
Principles of Channelization
1. It reduces the area of conflict in large
paved intersection. In view of uncontrolled
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vehicle and pedestrian movements it creates
congestions and accidents.
2. The speed of traffic stream at the
intersection may be controlled by the curvature
employed in the bending of the roadways. Thus the
minor flows will be sent to conform to the main
traffic stream.
3. Likewise, the speed of traffic stream at
the intersection may be controlled by funneling. A
scheme which not only controls the speed of
entering vehicles but prevents overtaking andpassing in a conflict area.
4. It blocks prohibited turns. To divert
traffic streams, islands may be employed to
encourage drivers in the strict observance of
prohibited turns.
5. It provides refuge for turning, and
crossing vehicles. Adequate shadowing provides
safe refuge for waiting vehicle to cross or enter
and uncontrolled traffic stream.
6. It is essentially required for an
effective signal control at intersection with
complex turning movement.
7. It provides location for the installation
of traffic control devices at the intersection of
multi lane roadways with complex turning movements.
Traffic Education
Traffic education is the crowning jewel of
traffic management, an abstract architect of social
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life and an unyielding master of mans destiny on
the roadways.
As one of the 5Es of traffic management, it is
a priceless gem in total gamut of social order on
the road, likened to an oasis in a desert of
roadways. Therefore, traffic education must be
free and there must no economic barrier to its
acquisition.
In sum, what is needed are men of courage and
vision to initiate reforms and craft a more viable
formula that will shape the future quality oftraffic education.
Considerations to Road Discipline
Considered in this light, what has to change is
not culture, but the heart and mind towards road
discipline. A vivid proof that discipline remains
in shaping force of our vision and it towers like
mountain above other values. Safe to say, what is
needed now is to harness the armed conscience of
the silent majority to cease to be silent and join
the crusade against the scourge of moral decay on
the roadways. For only by its fruits can we know
the tree.
Traffic Education as a Merchandize
Traffic education by itself is merchandize
difficult to sell, not only because it is
expensive, but there are varying shades of
acceptability among the masses. And the seeds of
reforms are not always sowed on fertile soil. But
without social transformation, all traffic laws,
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even with punitive sanctions will be ineffective in
the crusade to institute reforms. For there is no
way of inculcating new moral order into theconsciousness of uneducated people.
Mistaken Notion About Traffic Education
Many have the mistaken notion that education is
only the acquisition of knowledge, the accumulation
of facts of learning of information by rote.
Traffic education is more than just the absorption
of information and learning of skills. Trafficeducation is the making of a whole person, of a
human and humane being, of civilized or cultured
individual inculcation in the youth of norms, moral
and ethical behavior, good manners and right
conduct.
Complexity of Traffic Education
Traffic education is too complex to be covered
only by limited topics or by the volume of
scholarly books for it encompasses vast
intellectual novelties that cannot just be left to
the market forces of experts but to the
articulation of the academe. Having put the idea
forward, it must be pursued to the end to reap the
expected dividends. This is not the utopian
demand, but a challenge for a better future and new
order on the roadways.
Only with moral climate can we open new
frontiers and move toward new horizon and learn the
lessons of the past for the present and the wisdom
to know the difference that past failures should
not foreclose future successes.
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Environment
Environment is not a mere creative philosophy,
but a new vision with unique force that could
reshape the world of traffic management. In word
of scholar, environment is a single phrase that is
an anathema to purist and idealist but by word to
ecologist. It reflects the bountiful blessings of
nature in prestige form: tress in greenest state
and seas abounding with fishes and marine life,
until man like carpetbaggers, wrought wantondamages to contemporary damages.
It is about time that environment be
institutionalized as a pillar of traffic
management. For one of the real tragedies of
traffic administrator today is the failure of
traffic titans to incorporate environment as the 4th
E of traffic management. If the past experience is
any guide, there are just too many variables that
affect the system whose common denominator of
solutions is equated to environment. It is the
system which destroys and it is the system which
saves.
External Factor
Driving is not a theoretical fixture. In
driving, the attitudinal norms of drivers arevaried, subject to the tempo of time and space,
cultural relativism, values and environment.
Behavioral patterns of drivers are disturbed by
the external factor of environmental elements on
the roadways decreases the drivers skills, keen
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perception and sound judgment. If drivers are
unaware of these unwanted variables while cruising
the highways, they are courting dangers and thus,prone to accidents. The following are the common
external factors:
1. Heat
It is a form of energy which causes the body to
rise in temperature, to fuse and to evaporate that
can excite emotionally the drivers skill while
behind the wheels.
2. Storm
This atmosphere disturbance with strong winds
and rains is usually accompanied by thunder and
lightning. With these ambient atmosphere and
environmental mal-conditions, the drive on wheels
is affected physiologically and emotionally. At
the height of heavy downpour and torrential rains
the visual range is limited impairing his effective
control of the vehicle.
Under these adverse conditions, the driver must
have stock of theoretical and practical knowledge
in driving for experience alone is not sufficient
to measure proficiency.
3. Fog
Unlike the cloud which is visible mass abovethe earths surface, fog is condensed water vapor
in cloudlike masses that forms close to the ground.
This feature is its distinctive difference.
Sometimes fog is caused by masses of floating
materials of either dust or smoke that obscures the
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visibility of the driver to less than 1, 100 yards.
Irritated by this environmental phenomenon,
judgment of the driver is substantially affectednot knowing what to do and what not to do. Against
those backdrops, driver should be guided not by the
dictates of the heart but by the wisdom of the
mind.
In countries where the weather condition is
foggy, vehicle should be equipped with a yellow for
lights. Although there is negative finding that
yellow light does not totally penetrate the foggy
weather, however, in the absence of viablealternative, the usability of yellow fog lights has
its universal acceptance.
Internal Factor
Internal factors is a behavioral pattern of man
which appears early in life. Many voices are
advocating the hypothesis of relationship between
stress and environment. Even doctors failed to
identify the true traits of the individual which
most often do not surface in his personality test.
While today there is commonality of consensus
that internal factors reacts on the chemistry of
environment, still a need arises for savants to the
further flex their intellectual muscles to act as
arbiter of the present and future destiny of the
drivers tailored on human dimensions.
The following are the most common identifiableinternal factors that cause road accidents:
1. Personality
It is in this internal factor that distinctly
distinguishes an individual driver from other
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drivers in relation to environment. The qualities
of the driver constitute his personal being and
social traits. His personality is best tested whenconfronted by the greatest odds of the
environmental factors.
2. Character
From the beginning of time, the complex
characters as to behavior and habits, attitudes and
interests and personal philosophy in life
distinguishes a particular driver from the other.
Another scientific marvel is the discovery of a
detectable organism that is the result pf thepresence of gene or group of genes that
differentiates one driver from the other.
Driver may probably have developed the tenacity
for survival, but his character may yield to
massive onslaught of a violent environment, and
thus brook peril and misfortunes while behind the
wheels. Drivers by way of omissions succumb to
human lapses and adversarial curse of the
environment which may end in road accident.
3. Epilepsy
The word epilepsy is derived from the Greek
word, epilambanein,meaning to take hold. It is
defined as a chronic nervous disorder of the human
brain affecting the mans consciousness and
muscular control with various degrees of severity.
It may be congenital of brain damage caused bytumor, injury, glandular imbalance or toxic
substances and may result in convulsions or lost of
consciousness.
4. Sleeping Sickness
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A chronic disease e occurring in tropical
countries like Africa, this is caused by parasites
trypanosoma gambiense and rhodosiense andcarried by flies.
It causes fever, physical and mental lethargy,
and very often death. It also occurs in Central
Africa and commonly called encyphalitis
lethargica.
What is pathetic is that this incidence becomes
common to drivers while cruising along the mountain
trails and forested areas, when stung by theseinsects, the tendency of the drivers body function
is to diminish or at worst, cease. This in effect
is an ominous sign that danger lurks ahead as the
driver may lose control off the vehicle which may
ultimately end in road mishap or may flung into the
deep ravine.
Threats to Environment
As one travels on the highways or roadways,
probably they are unmindful of the following
environmental threats to man and nature:
1. Greenhouse Effect
Scientifically, the greenhouse effect is a
natural phenomenon that makes earth habitable,
without which the earth would be frozen like Marsand other celestial bodies.
2. Ozone Depletion
The disastrous effect of ozone depletion is the
uncontrolled emission of ultra-violet light and not
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climatic change. Ozone per se is an allotropic
form of oxygen created when oxygen molecules are
bombarded with ultra-violet rays from the sun. Ifthe ozone layer fails to absorb the ultra violet
rays from passing the earths surface, the ultra-
violet radiations causes skin cancer and cataracts.
3. World-wide Effect
Change in UV-B radiation may have been caused
by a chemical reaction as a consequence of gases
spewed into the atmosphere by volcano eruption.
Other scientific findings have reported thatmeasurements by satellite and by high-altitude
balloons detected record of thinning of ozone due
to volcanic eruption.
4. Effect in Climate
The transition fro the Ice Age to warmer
weather in which our civilization flourished took
only a few decades, and the climate could change as
quickly as possible.
Motor Vehicle its Effects to Environment
In so many words the major environmental
effects of the use of motor vehicles are air and
noise pollution:
1. Air Pollution
The most lethal effect of motor vehicle is the
pollution caused by engine exhaust. The finding
shows that the carbon monoxide emission has higher
percentage in highly urbanized areas.
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Air pollution is usually measured in terms of
concentration of pollutants over time, such as
parts per million of air per hour or in terms ofpollution to vehicle usage in grams per vehicle-
mile.
The primary pollutants in motor vehicles
exhausts are carbon monoxide (CO); hydro-carbons
(HC); nitrogen oxides (NO); mostly nitrogen
dioxide; lead (Pb), and particulate matter.
Likewise, larger engines emit considerable amounts
of sulfur oxides (SO), mostly sulfur dioxide.
2. Noise Pollution
Less dangerous than air pollutions, but
admittedly more vexing and annoying, is the problem
of vehicular noise. Of several sources of
vehicular noise, the cars tire-roadway interaction
and truck exhaust noise have been identified as the
primary cause of noise pollution.
Noise levels are measured in decibels (dB) on a
logarithmic, rather than in arithmetic scales.
Study showed that a decrease of only 10dB would
whisper at 5 feet (1.5 m) will register about 34
dB; the interior of a quiet office will average 55
dB; and the sound level at the side of an
expressway may be as high as 90 dB.
The effects of traffic noise on human seem to
be more psychological than physiological. Severalstudies have pointed to annoyance as being the
widespread effect. There is no question that
highway noises alone can causer hearing damage, but
the effects of noise annoyance on behavior and
mental health cannot be disregarded.
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Pollutants Caused by Motor Vehicles
The following pollutants are known to cause
damage to vegetation and thus, to man:
1. Ozone
As a component of the photochemical complex,
ozone is considered to one of the most damaging air
pollutants to vegetation. Ozone produces acharacteristics fleck of stipple on the upper
surfaces of sensitive plants. Prolonged exposure
or high concentrations will cause complete tissue
collapse.
2. Peroxyacyl Nitrate (PAN)
PAN can produce the characteristics systems of
glazing or bronzing of the lower surfaces of the
younger leaves of sensitive plants. Even a low
concentrations, i.e., 0.01 ppm for 8 hours, PAN
produces chlorosis and early senescence.
3. Hydrocarbons
Ethylene is the only hydrocarbon from vehicle
exhaust that is known to cause a variety of
symptoms in many plants, including early
senescence, chronic injury, flower and fruit drop,and growth suppression.
4. Carbon Monoxide
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The effects produced by carbon monoxide are
similar to those of ethylene; however, the
concentrations must be very high.
5. Petrol Additives
Lead, nickel, boron and manganese are known to
be toxic to plants to accumulate in sufficient
quantities. The additives may accumulate in plant
tissue without injuring the vegetation, but they
may prove toxic to animals and human being who
obtain food from these plants.
The Laws of Nature as Applied to Motor Vehicles
Some of known laws of nature that affects the
skill of the driver and efficiency of the machine
in relation to environment are as follows:
1. Inertia
It is the first law of motion as espoused by an
undisputed man of science.
1) Inertia of Rest
Any object at rest will remain at rest
unless no external factor forced it to move. This
is the reason why it is difficult to push stalled
vehicle at rest.
2) Inertia of Motion
Any object in motion will constantly move
in straight line unless other forces intervene to
change its speed or course. This explains why a
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stalled vehicle when in motion finds no greater
obstacle to gain momentum of speed. This law of
motion gives birth to the development of seat beltand other accessories to cushion the impact from
the abrupt change from inertia of rest to inertia
of motion.
2. Centrifugal Force
A scientific term of force that pushes a moving
object in circular motion away from the center. To
better understand its effects, if a ball is tied to
a string and whirled around in fast speed, thepulling of the ball in circular path away from the
center is known as centrifugal force. And is the
string breaks from the ball it shall not follow the
circular path of motion but will follow the
direction where the string breaks.
Similarly, a car negotiating a curved road is
subject to same force as the ball and string model.
The car is to the ball and the string to the
friction between the tire and the road. Thus, if
the friction breaks the car will skid or careen-off
the roadways.
To cushion the effect of centrifugal force on
curve roads, man has developed three kinds of road
surfaces on curves, these are:
1) Crowned Curve
Is designated to better serve the drainage
system but not necessarily the safety factor,
especially on high speed. The curve according to
studies, press the car against the road surface, in
effect lessening the friction between the tires and
pavements.
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2) Flat Curve
According to authorities it offers no
resistance to skidding onward, hence, dangerous at
high speed.
3) Bunked Curve
Of the three, bunked curve is unquestionablythe best for the inertia of motionit is
counteracted by the nature of the road on the car.
3. Gravity
Simply stated, it is a kind of force that tends
to pull all objects to the center of earth. To the
layman, the effect of gravity can be better noticed
when a car is negotiating an uphill trend. Because
of the gravity, it needs to accelerate its power to
counter-balance the pull.
But in downhill course, driver should be extra-
cautious because of the braking force of the engine
pull and gravity pull are on the same direction and
must be counteracted, otherwise the car may careen
off the roadway if uncontrolled.
It should be noted that the center of gravityof an object is the point where its weight is
evenly balance. This is the rationale why the car
designsthe center of gravity is taken into
consideration to forestall a turn-turtle when the
car suddenly changes its course while in motion.
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4. Kinetic Energy
It is an established fact that anything thatmoves possesses this kind of energy. It is safe to
conclude, therefore, that any energy of motion is
denominated as kinetic energy.
To better appreciate its importance, a car
traveling at higher speed demands a period of time
before it can totally stop, because the greater the
speed of moving object, the greater it is kinetic
energy. Unless the driver is conversant of the
implication of this law of nature, he is at perilto meet an accident on sudden brake.
5. Friction
It is that kind of natural force that causes
resistance of one surface against the other when it
comes to contact. This could be better observed
when a car either moves or starts.
According to studies, the increase or decrease
of friction on the pavements depends whether the
road is dry or wet. However, there are three
factors that could reduce the road-wheel friction.
1) Weather condition.
2) Worn tire thread.
3) Bumpy road.
6. Force of Impact
The amount of force when two objects collide is
known as force of impact and it expressed in
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pounds. This force according to authorities is
determined by:
1) The speed of the moving object and the
angle at which they collide.
2) The weight of the object or objects.
3) The distance within which an object is
stopped after the initial impact.
Economics
Economic, oils the wheels of traffic. Time
has come that the economics of traffic be rescued
from the barred waste of wrong perceptions:
traffic and economics are strange bedfellows and
their unity in diversity is a mere fiction.
Experts must have an open mind not just revite4d to
the narrow confines of 3Es of traffic and refuse
to look beyond the costly illusion of its advocate.
These are decisions that might be charting
unpopular course but hope to give shapes and sinews
to empty illusions of the past and to look forward
to the new complexion of the present system with
new vision of the future: the crowning of the 5th E
of traffic, economics.
This is not a choice of necessity but signs of
time. For decades, scholarly studies have noted the
fast decline of the 3Es philosophy from thepedestal of respect and the patterns is traceable
to the shifting demands around the world. The fact
that there is indeed a mountain of books in the
fields of 3Es does not alter the unseen forces of
recession.
Economic-Traffic Interactions
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Human gregariousness craves for many wants and
seems to admit no satisfaction: problems begin.But all of these wants are not free and can only be
acquired at the altar of sacrifice: most goods are
scarce. Goods are not necessarily chosen to
satisfy basic wants either directly or indirectly.
Capital goods are produced for industries to
produce goods for consumption. The element of
choice on how to satisfy the present wants for the
future wants.
Even with modern infrastructure as analternative solution to the ills of traffic will
put to naught if the resources is scarce, a
classical balancing interaction of traffic and
economics.
Economics as the 5th Es of Traffic
Non-incorporations of economics as the 5th Es
of traffic is complex pattern that traffic taipans
would find it difficult to defend. As long as
these traditional thinking experts refuse to veer
away from the old-school to the modern traffic
ideology, then we are creating more problems than
solutions on the road.
This argument is broadened further by the
studies that technocrats are guided and influenced
by their own self interest in shocking disregard ofthe changing world behavior on the traffic system.
Traffic Accident Investigation
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Successful traffic accident investigation
requires considerable basic background knowledge.
To know what question to ask, and what to look for,you must also have some fundamental ideas about
accidents and their causes. To avoid wasting time
and making mistakes, especially during the urgent
activities at the scene of an accident, you need to
plan what you are going to do and to continually
revise your plan as you proceed.
What is a Traffic Accident
A traffic accident is that occurrence in a
sequence of events which usually produces
unintended injury, death, or property damage, or a
traffic accident is something happened that was
not expected. Criminal charges arising out of
traffic accidents are mostly due to negligence on
the part of the driver. Negligence means failure
to take proper care.
There are two (2) main kinds:
1. Errors of Commission
Where a person does thing that he should
not have done.
2. Errors of Omission
Where a person does not do something heshould have done.
Classification of Traffic Accidents
1. Motor-Vehicle Traffic Accident
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Is any motor-vehicle accident occurring on a
traffic way, for example, the ordinary collision ofmotor vehicles on a highway?
2. Motor-Vehicle Non Traffic Accident
Is any motor vehicle accident which occurs
entirely in any place other than a traffic way, for
example, a motor vehicle accident on a farm or in a
private driveway?
3. Non Motor-Vehicle Traffic Accident
Is any accident occurring on a traffic way
involving persons using the traffic way for travel
or transportation, but not involving a motor
vehicle in motion, for example, collision between a
pedestrian and a bicyclist on a sidewalk?
Definition of Motor Vehicle
It is every device which is self-propelled and
every vehicle which is propelled by electric power
obtained from overhead trolley wires, but not
operated upon rails.
Definition of Traffic Way
It is the entire width between the boundary
lines of every way or place of which any part isopen to the use of public for purposes of vehicular
traffic as a matter of right or custom.
Chain of Events of a Traffic Accident
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1. Perception of Hazard
Is the seeing, feeling, or hearing andunderstanding the unusual and unexpected movement
or condition that could be taken as a sign of the
accident about to happen.
2. Encroachment
Is the movement into the path assigned to
another traffic unit, perhaps the most important
encroachment is crossing a center or barrier line.
Another is entering a crosswalk when it is
occupied. Pedestrians can encroach on the pathassigned to motor vehicles.
3. Leaving the Roadway
Is the moving off the roadway, Roadway is
that portion of traffic way which is improved,
designed, or ordinarily used for vehicular travel
exclusive of the shoulder. The event takes place
when one wheel of the vehicle may leave the
roadway. A vehicle may leave the roadway on the
left as well as on the right side.
4. Leaving the Road
Is the moving off the road and shoulder, if
any, this may mean going into the ditch or over a
curb. The event takes place when one wheel of the
vehicle climbs the curb or goes off the shoulder,
5. Initial Contact
Is the first accidental touching of an object
collides with by a traffic unit in motion, before
this, there is no force between the objects
colliding, and afterwards there is force.
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1. Running off the road.
2. Non-collision on the road.
3. Collision on the road.
Classification of Accident According to Severity
1. Property Damage
It is nay motor vehicle accident in which thereis no injury to any person but damage to the motor
vehicle, to other property including injury to
animals.
2. Non-Fatal
It is any motor vehicle accident that results
in injuries other than fatal to one or more
persons. The injuries maybe as follows:
1) Fatal Injury
It is an injury that results in death
within 12 months of the motor vehicle traffic
accident.
2) Serious Visible Injury
It is a bleeding wound, distorted member,or any condition that requires the victim to be
carried from the scene of the accident. Consider
the injury to be visible if symptoms are present
even though the injury itself is not visible.
3) Minor Visible Injury
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It is an abrasion, bruise, swelling,
limping, or obviously painful movement.
4) Non-Visible Injury
It is complaint of pain without visible
signs of injury; or momentary unconsciousness.
3. Fatal
It is any motor vehicle accident that resultsin fatal injuries to one or more persons.
Crucial Events
It is used instead of key event to characterize
what occurs to each traffic unit individually
rather than to the whole accident and with
reference to the available path rather than the
entire road.
Crucial Events in a Traffic Accident
1. Leaving the available path, not the same
as running of the road.
2. Turning over in the path without
collision.
3. Other non-collision in path.
4. Collision with non-traffic object in or
adjacent to the path.
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5. Collision with other traffic unit in the
path, not marked vehicle.
The Three Points in Traffic Accident
1. Point of Possible Perception
It is the place and time at which the unusual
or unexpected movement or condition could have been
perceived by a normal person. This point always
comes at or before the point of perception. Delayin perception or perception time between the point
of possible perception and the actual perception.
If the hazard is actually perceived as soon as
nearly as possible, perception is said to be
prompt. Maximum delay of perception occurs when
the traffic unit does not sense a hazard until hit
it.
The perception point and the point of possible
perception are used mainly in trying to discover
and evaluate contributions of drivers and
pedestrian to accidents. Did the driver do
anything or fail to do anything before the
perception point that contributed to his
difficulty. Inattention is probably the most
common contribution of driers to their delayed
perception; but speed is a common contributor to
accidents before perception point. The perception
point is particularly useful in trying to discoverwhat the driver or pedestrian did or should have
done but did not do to avoid the accident or to
make it less serious.
2. Point of No Escape
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Is that place and time after or beyond which
the accident cannot be prevented by the traffic
unit under consideration. Nothing the driver orpedestrian can do will save him from this point on,
although he still may be able to mitigate the
accidentfor example, by slowing down as much as
possible before a collision. Sometimes the point
of no escape and point of perception are the same.
Sometimes the point of no escape comes before the
point of perception, for example when a persons
attention is diverted until just before the crash.
Often the point of no escape comes after the point
of perception. This circumstance generallyindicates faulty judgment on the part of the driver
in his attempt to prevent the impending accident.
3. Point of Impact
It is term which, although widely used in
connection with traffic accidents, does not seem to
have very precise meaning. Impact generally means
the same thing as collision but it also means the
force involved. Point of impact is sometimes used
to mean the same as point of initial contact,
sometimes used to mean the same as point of maximum
engagement and sometimes center of force. Because
the term has varied meanings, other more specific
terms are preferable.
Technical Aspects of Traffic Accident Investigation
The traffic accident investigator should know
how to make proper sketch of an accident with
correct measurements of all the important data. He
should know how to photograph the scene of the
accident properly, to show the important facts. He
should know what kind of physical evidence to look
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for in hit-and-run cases. He must know how to get
the facts, records the facts correctly, and then
figure out what happened in order to help theprosecutor present the case in court.
Definition of Attributes
An attribute is any inherent characteristics of
a traffic way, a vehicle or a person making a trip
on a traffic way that affects the probability of a
traffic accident.
Purposes of Traffic Accident Investigation
1. Everyone involved is curious about causes
and circumstances of the accident.
2. Police are also interested in finding out
whether there is enough evidence of law violation
in the accident to take enforcement action.
3. Insurance agencies and adjusters want to
determine negligence on the part of the drivers
involved in the accident so that damage claims can
be properly adjusted.
4. Government officials and other concerned
authorities want specific information about
accidents to know better how to prevent future
accidents.
Basic Steps in Traffic Accident Investigation
1. Go to the scene as quickly as possible.
2. Park correctly to avoid further collision
and facilitate traffic flow.
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3. Assess the situation and call for whatever
assistance is necessary.
4. Care to injured and protect their personal
property.
5. Protect the scene against additional
collision.
6. Locate drivers and establish identities.
7. Interview drivers, participants andwitnesses.
8. Note and record physical conditions at the
scene, locations of vehicles and evidence.
9. Take photograph when possible
10. Test and inspect the vehicles when
applicable.
11. Arrest or cite violators when applicable.
12. Have the scene cleared up.
13. Follow-up at the hospital.
14. Notify relative and survivors.
15. Prepare reports.
Levels of Activity in Accident Investigation
1. Reporting
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2. At-scene Investigation
3. Technical Preparation
4. Professional Reconstruction
5. Cause Analysis
Hit-and-Run Investigation
The search for physical evidence at the scene
of a hit-and-run accident must be done properly andquickly because it is not possible to close-off and
guard the scene of this kind of crime? The roads
must be cleared to permit ordinary flow of traffic
as soon as possible? Another problem is that
passing vehicles will crush of blow away important
pieces of small physical evidence. The following
are the good ways of searching the scene of a hit-
and-run accident:
1. Look over the ground at what seems to be
the point of collision.
2. Follow the path that the vehicle took in
leaving the scene to find out if it left tire
prints in the soft dirt, or where parts of the
vehicle or broken glass fell off as is drove away.
3. Study the objects the vehicle has struck
to see if there is a transfer of physical evidencelike paint.
4. Look for things that may have spilled from
the vehicle.
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The investigator should collect all materials
found at the scene of the crime which cannot
satisfactorily explained. Broken parts of themotor vehicle are the most important physical
evidence in hit-and-run accidents. When the broken
parts match parts still on the car, this is a good
positive identification. Broke parts are more
important than damaged parts. Part of a broken
bumper of door handle is better than a damaged
hubcap.
Proving Driving
In all case of traffic offense, intoxicated
driving or hit-and-run, the first and most
important thing that must be proved is that the
accused person was driving the car at the time of
the offense. This can be done either by eye
witnesses or by physical evidence. But it must be
proved. The investigator must not assume that the
owner of the vehicle was the person actually
driving it.
Nature of Common Hit-and-Run Cases
1. Run over of pedestrian crossing on the
roadway or crosswalk.
2. Sideswiped of pedestrian on the sidewalk
or road shoulders.
3. Collided with a moving vehicle while
overtaking on same direction.
4. Collided with a moving vehicle while
overtaking on opposite direction.
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5. Damaged parked vehicle along the roadside
and parking areas.
6. Crushed police road blocks.
7. Bumped stray animal on the roadway.
Technical Preparation
Delayed traffic accident data collection and
organization for study and interpretation. Thedata collected are essentially factual. Technical
preparation includes making additional measurements
and photographs, preparing maps and diagrams,
simple speed estimates, matching damage areas, and
making experiments to obtain specific data. It is
third level of traffic accident.
Triangulation
A method of locating a spot in the area by
measurements from two or more reference points, the
location of which are identical for future
reference. Compare with coordinates.
Determining Speed from Skid marks
One of the most common problems in accidentinvestigation is: How fast was he going? it is
difficult question to answer, but speeds in excess
of the legal limits are important to the police,
because they must decide if the driver did his best
to avoid accidents. The criminalist cannot
determine exactly how fast a vehicle was traveling,
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but he can make a very good estimate by
mathematical calculations based on the skid marks
left by a vehicle before the collision. It isimportant that the field investigator take correct
and accurate measurements to help the criminalist
make correct calculations.
Skid Marks
Skid marks are marks lefts on the road by tires
that are not moving because the brakes are applied
strongly enough to lock the wheels. There are two(2) kinds of skid marks:
1) made by a car going straight ahead, and
2) made by a car going sideways.
The second type is commonly called scuffs.
It is important not to confuse skid marks with tire
prints. Tire prints indicate that the wheel was
still turning. Tire prints should not be used in
calculating speed. To make an accurate estimate of
speed, it is important that the marks of all four
tires are obtained.
A car is always going faster than the speed
calculated from skid marks, because in addition to
losing speed in sliding as shown by the skid marks,
the car also losses its speed in one or more of the
following ways:
1. Skid marks do not happen until the tire
slides far enough to get hot enough to smear the
rubber on the paving.
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2. The total distance of the skid marks
cannot be seen because the car hits something
before stopping.
3. Some braking action occurs before the skid
marks appear.
4. The brakes are not put on hard enough to
lack the wheels.
In accidents with pedestrian, the skid marks
are most reliable because there is nothing to stop
the forward movement of the car. In a collisionaccident, the amount of damage to the cars must be
considered in determining the reliability of speed
from skid marks.
Scuffmarks
A friction mark on pavement made by a tire
which is both rotating and slipping, acceleration
scuff yaw marks, flat tire marks.
Skip-Skid
A braking skid marks interrupted at frequent
regular intervals, the skid mark made by a bouncing
wheel on which brakes keep the wheel from turning,
compare with gap skid.
Gap Skid
A braking skid marks which interrupted by
release and reapplication of brakes or which
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terminates by release of brakes before collision,
compare with skip skid.
Flip
The movement of vehicle without touching the
ground from a place where its forward velocity is
suddenly stopped by an object such as curbs or
furrow-in below its center of mass with the result
that the ensuing rotation lifts vehicle off the
ground. A flip is usually sidewise, but if it isendwise, it is spoken as a vault.
Length of Vehicle
The investigator sometimes makes mistakes of
determining the speed from the total length of the
skid marks he finds. Remember that the beginning
and end of the skid marks may include both the
front and rear wheels of the car and unless it is
possible to measure each wheel base, distance
between the middle of the hubcap of the front wheel
to the middle of the hubcap of the back wheel,
should be subtracted from the total length of the
skid marks.
Grade or Slope
Grade or slope means the steepness of a hill
and is important in calculating speed from skid
marks, because a car going downhill take longer to
stop than a car going uphill, or slope is the
number of meters the road rises for each meter of
level distance along the road. The resulting
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number is less than 0.1 except for very steep hill.
It can be measured by using traffic template or
with an ordinary carpenters level. Put thecarpenter level on the road with one end uphill and
the other down. Raise the down hill end until the
bubble centers. Hold the level in that position
while you measure the distance from the bottom of
the level down the road. Divide this distance by
the length of the level. For example, if the level
is one meter long and lower end is one centimeter
off the ground the grade would be 0.01.
Calculation of Speed from Skid marks
There are charts and tables and even special
measuring devices from which the speed can be
calculated from the skid mark. The criminalistic
investigator, however, should understand the exact
mathematical formula which the speed is calculated
because he may ask by the judge in court to explain
how he arrived at his estimate. The formula is not
difficult and the only hard part is determining the
square root. This can be easily done by means of a
set of tables or a slide rule, but in the range of
measurement with which the investigator is
concerned, there is a simple formula for
determining square root that is sufficiently
accurate for the purpose.
Find the nearest number to your measurement
which has an even square. Example: 4, 9, 25, 36,64, 81, 100, etc. If the number in your
calculation is 30, for example, the closest number
is 25 which is only 5 numbers away rather than 36,
which is 6 numbers away. Since 5 X 5 equals 25,
divide your number by 5, then average the result by
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the divisor, and you will get a square root
sufficiently accurate for the purpose.
Formula:
S = 15.9 d X (F + g)
-
Where:
S = speed in kilometer per hour
d = slide-to-stop distance in meters
g = grade or slope
F = drag factor
or
S = 5.5 d X (F + g)
-
Where:
S = speed in miles per hour
d = slide-to-stop distance in meters
g = grade or slope
F = drag factor
Example:
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A vehicle going down hill with a slope of 0.15
and a drag factor of 0.70, leaves a skid marks of
20.6 meters. What is the speed of the vehicle?
1. SPEED = 15.9 20.6 X (0.70 - 0.15)
The vehicle is going down hill, so the grade is
negative and is subtracted.
2. SPEED = 15.9 20.6 X 0.55
= 15.9 11.33
The nearest whole number whose square is
closest to 11.33 is 3 (3 X 3 = 9).
3. 11.33/3 = 3.78
4. 3.78 + 3 = 6.78/2 = 3.39
5. SPEED = 15.9 X 3.39 = 53.90 km/hr
All calculations are resolved in favor of the
driver, so:
6. SPEED = 54 km/hr
Factor
Any circumstances contributing to a resultwithout which the result could have not occurred;
an element which is necessary to produce the
result, but not by itself, sufficient, operational
factor and conditional factor.
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Operational Factor
Functional failure of the highwaytransportation system that contribute to the cause
of traffic accident. The failures may be
malfunctions or perception, decisions, or
performance in trip planning driving strategy, or
evasive tactics.
Sequential Factor
Factors which must be present at the same time
to contribute to the cause of an accident,generally operational factors.
Simultaneous Factor
Factors which must present at the same time to
contribute to the cause of accident, generally
condition factor.
Drag Factors
It is a number representing the acceleration or
deceleration of vehicle or other body as decimal
fraction of the acceleration of gravity, the
horizontal force needed to produce acceleration in
the same direction divided by the weight of the
body to which the force is applied. When a vehicle
slides with all the wheels locked, the coefficientof friction and drag factor have the same value.
Co-Efficient of Friction
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The number representing the resistance to
sliding of two surfaces in contact; the drag factor
of a vehicle or other object sliding on a roadwayor other surfaced required to keep an object
sliding on that surface in motion, divided by the
force of the object against that surface, measured
in pounds per pounds, often designated by the Greek
letter Mu.
Reaction Time
The time from perception to reaction.
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ANSWERS TO REVIEW QUESTIONS IN TRAFFIC
MANAGEMENT & ACCIDENT INVESTIGATION
===========================================================
1. B 26. C 51. C 76. A
2. C 27. C 52. A 77. B
3. A 28. A 53. B 78. A
4. A 29. A 54. D 79. B
5. B 30. C 55. C 80. D
6. A 31. A 56. A 81. C
7. B 32. B 57. C 82. A
8. B 33. A 58. A 83. C
9. B 34. D 59. B 84. B
10. A 35. C 60. D 85. A
11. D 36. D 61. C 86. B
12. A 37. A 62. C 87. D
13. C 38. B 63. B 88. A
14. D 39. D 64. B 89. A
15. D 40. C 65. A 90. B
16. B 41. A 66. B 91. C
17. C 42. B 67. D 92. D
18. C 43. B 68. A 93. D
19. D 44. D 69. A 94. C
20. D 45. B 70. B 95. D
21