Traffic Management

Traffic Management

Learning objective: Demonstrate the safety management and strategies Demonstrate the accident prevention strategies and various diagnosis framework

Learning outcome:At the end of this lecture, successful students will be able to:

Recognize existing safety management and strategies in Malaysia Identify the method for accident reduction Recognize accident prevention strategies Identify various diagnosis framework

1.0 Introduction

Traffic management techniques are designed to deal with both stationary and

moving vehicle, and the pedestrian. The techniques are primarily concerned with

the following

a) Reducing accidents.

b) Minimizing vehicle-pedestrian interactions.

c) The control of standing vehicles, e.g. by restriction of waiting, loading and

unloading, and stopping.

d) The control of moving vehicles to reduce conflicts and to ease traffic flow,

e.g. by one way streets, tidal flow schemes, banning of turning movements,

and the utilization of automatic traffic signals and signs.

2.0 Facts of Accident

The results of many studies into motor cyclist associated accidents have resulted

in the following conclusions:

a) The personal injury accident rate of solo motor cycles is about 4 times the rate of

cars.

b) The risk of a motor cyclist being killed per mile travelled is about 20 times that of

the chance of a car driver being killed.

c) Ninety seven percent of the casualties which occur as a result of collisions

between motor cycles and motor vehicles are the motor cyclists.

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d) The risk of death or serious injury to a pillion passenger is about 5 percent greater

than the risk to the driver.

e) Motor cyclists with less than six months’ experience have about twice as many

accidents per head and per mile as those with more experience.

f) Most of the motor cyclists who are killed, and many of those who are injured,

receive head injuries.

Meanwhile, the ratio of road accidents in darkness to those in daylight is about 1.5

to 2 in dry weather and about 3 to 4 in wet weather. This is also related to the

effects of good street lighting. From research, good street lighting reduced the

average frequency of injury accidents in darkness by about 30%.

3.0 Accident Reduction

Road Research Laboratory has carried out a most intensive programme of

research to find out methods of reducing the frequency and number of accidents,

and of facilitating traffic flow.

Following are typical methods of accident reduction.

a) Improvement of Intersections

One of the most fruitful applications of traffic management lies in the

improvement of highway intersections. This is mainly because very often

minor improvements can be carried out without affecting the layout and

design of the highway as a whole, but yet may reduce accidents and improve

highway safety beyond all proportion to their costs.

b) Improvement of driver characteristics

The most complex and least understood of every road problem is the human

one. Repeated studies indicate that errors of judgement are important factors

in over 90 percent of all highway accidents.

Following are some of the factors affecting driver characteristics:

Vision – good vision is a prerequisite of safe driving since it

accelerates the process of perception-reaction to traffic situations.

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Visual acuity – ability to focus quickly and to see clearly without a

blur.

Fatigue – the effect of fatigue brought on by prolonged driving, poor

living conditions and extreme anxieties.

Night vision – ability to see under low illumination, see against

headlight glare and distinguish between various colours at night.

Depth perception – skill which requires good teamwork of both eyes to

enable the driver to judge relative distances and to locate objects

correctly in space.

Alcoholic drinks – alcohol has very noticeable effects on driver

behaviour. It lowers the mental and physical efficiency by producing

slow and undependable responses.

Driver training – drivers shall be trained and educated to eliminate bad

driving habits, which might lead to undesirable reactions.

c) Engineering counter measure

Following are four strategies for road accident reduction through the use of

engineering counter measure:

i) Blackspot Approach

Identify the sites with higher than average number of accidents

(blackspot)

Identify a pattern occurred and common factors that caused the

pattern

Identify appropriate treatment

ii) Mass Action Plan

Involve application of a remedy to locations with common

accident problems

For example, to reduce wet skidding related accidents, a new

formulation to the road surface texture is required at certain

locations

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iii) Route Based Measure

Involve application of a remedy along a route with a higher

accident rate

For example, to reduce motorcycles related accidents, an exclusive

motorcycle lane is provided along a route

iv) Area Wide Measure

Take into account all factors that affect road safety including the

distribution of traffic over the road network

A complete and combination of various strategies for road safety in

a region

4.0 Identifying and Prioritizing Accidents

Accident and casualty analysis is a complex procedure because the factors

affecting accident occurrence are numerous and not independent. Ideally, the

direction that a comprehensive accident analysis takes will be led by accident

data. Experienced road safety engineers will carry out the analysis. They will

understand the importance of different types of result and be able to identify and

balance conflicting levels of accident risk.

In practice, the basic approach for urban and rural accident analysis can both be

summarized in the following steps.

i) Look at injury accident data for the relevant area for a period of three to five

years. Plot the locations of accidents on maps. This can be done with a GIS

system or an accident analysis package, initially distinguishing killed and

seriously injured (KSI), child accidents and/or other vulnerable groups

separately.

ii) Examine accident patterns in terms of type, contributory factors and location,

considering accident numbers and rates for each class of road.

iii) Identify any significant changes in accident trends and factors overtime.

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iv) Identify existing road safety devices available in the locations of accidents.

v) Checking on road geometry design in the locations of accidents.

vi) For each road in the area, tabulate the results.

vii)Prioritize roads for further investigation and treatment.

It may be helpful to tabulate the results of the analysis, to assess the relative

seriousness of problems to help prioritize them. This will be particularly useful in

identifying overall problems, such as speeding, skidding or bend accidents. It may

provide justification for a mass action treatment.

The information used on accident rates during the prioritization process will vary,

depending on the situation and the quantity and reliability of exposure data. The

use of more than one type of accident analysis approach will often be appropriate.

When ranking problems, a balanced assessment of all the data has to be achieved

based on:

i) Accident rate

ii) Number of accidents

iii) Severity of injuries sustained in accidents

An intervention level is a numerical value of a measure of an accident problem

(such as accidents/year, accidents/vehicle-km). If the values for a particular road

exceed the relevant intervention levels, then select that road for more detailed

analysis and subsequent treatment. Over time, most of the worst accident problem

sites have been cured.

Accidents now tend to be spread more evenly across whole areas. For this reason,

mass action, route action or area action remedial treatments may be preferable to

treatments at a few specific sites. The treatments selected may be chosen to tackle

one or more particular types of accident, rather than all accidents. Low cost

measures may make these other approaches just as cost-effective as the traditional

site-specific approach. In addition, some accident problems may be tackled more

effectively through enforcement, training and publicity than by engineering alone.

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5.0 Pedestrian Accidents

In the year of 1960, the following pedestrian accident statistics were recorded:

a) 72,214 pedestrians were injured in road accidents. These accounted for

approximately twenty percent of all highway casualties.

b) Four percent of the pedestrian casualties were fatalities.

c) Over 90 percent of the pedestrian casualties happened in built-up areas.

d) Over 50 percent of the pedestrian fatalities occurred in rural areas.

e) Approximately 94 percent of the pedestrian casualties happened on the

carriageway, the remaining 6 percent occurring on footpaths and refuges.

f) Pedestrian accidents were highest on trunk roads and lowest on unclassified

roads.

g) 72 percent of the pedestrian casualties occurred during day-light.

5.1 Management Measures of Pedestrian Accidents

Most pedestrian management measures are aimed at segregating the pedestrians

from the vehicular traffic. When complete physical segregation is not possible,

controls are aimed at restricting pedestrian movement on the carriageway to

particular locations, and if possible, during particular times. Common

management measures are as follows:

a) Pedestrian channelization

b) Pedestrian signals

c) Pedestrian crossings

Segregated crossing – subway or bridge

Zebra crossing

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