Ogden Chapter 1: Safety Management System. Road Safety Analysis The nature and extent of the road safety problem with regard to humanitarian, public health

Ogden Chapter 1: Safety Management System

Road Safety Analysis

The nature and extent of the road safety problem with regard to humanitarian, public health or economic aspects need to be investigated.

There is a need to respond to this problem scientifically, not base on the judgment and emotion.

There used to be prejudice, hunch, opinion and guesswork (PHOG) approach to the road safety problem.

Process of road safety management

Haight (1983) suggested that the management of road safety has advanced in eight important ways:

There is no cure• The consequences of mobility is inevitable, but

certainly we can take steps to minimize them.• Devoting on-going management system will help to

have safer mobility.• The management system need to use scientifically-

based techniques which would help to determine if safety resources are correctly and effectively spent.

• The goal is to reduce problem to an acceptable and manageable proportions.

Process of road safety management (Cont.)

Abandoning the concept of cause and blame

• There was not any progress to reduce the road trauma, until the concept of cause and blame abandoned.

• Once we moved away from that concept, there was a need to determine the human capabilities when provided certain information to make decisions.

• A road crash is a consequence of certain events including irresponsible driver behavior.

• Those who design the vehicles and roads, should design for human error.


Consequences not accidents

• Much more effective approach is to reduce the losses.

• there are three phases involve in a crash• Pre-crash• In-crash• Post-crash

• Rather than putting all our attention in crash prevention, we need also to reduce the in-crash trauma when a crash occur(e.g. seat belt usage).


• Providing the post-crash treatment to reduce the losses(e.g. emergency responses).

• Neither seat belt nor emergency services prevent crashes, but both have been very effective in reducing the extent and cost of road trauma.

Exposure

• Crash losses can be reduced by reducing the exposure to hazardous situations using management strategies.

• An effective strategy could be reducing the exposure of at risk groups, particularly younger drivers(e.g. curfews, alcohol use restrictions while driving.


• Exposure is often misinterpreted as a crash rate, while crash rates are of little value in selecting countermeasures.

• When an intersection has a high crash rate, it might in fact carries a lot of traffic.

• The crash frequency is important not the crash rate.

Statistical Analysis• The importance of scientifically-based analysis

implies two parameters which are fundamentals to road safety engineering.

1. Good database

2. Skill for interpretation and analysis of data.


• There are Limitations and shortcomings to crash databases.

Possible counter-intuitive outcomes

• The prediction of the effects, which are based on hypothesis and known facts, often get away from the right path.

• As Forrester’s law says that “in any complex system, the results of any action are always counter-intuitive.”

• Most engineers are skeptical from programs that have not been carefully evaluated.

• Perfectly sensible ideas may not actually work in practice.


Evaluation

Proposals need to be evaluated in order to understand what measures may be appropriate in response to crash situations.

Rational Priorities

• There is a limited budget for many competing claims in road safety. Therefore evaluation and implementation of a program not only should reduce the crash rate, but the benefits of such a program must exceed its costs.


• ID expenditures that will be more beneficial than others.

Historical development of approaches to road safety

There has been progress toward road safety problems through six stages:

Mono-Causal casuistic approach• Every accident was a problem and solution for that was

taking away the cause.

Historical development of approaches to road safety (Cont.)

• No attention was paid that taking away one problem may produce other problems.

• It is impossible to find a unique solution to every different problem.

• This approach promote perfectionism and led to attitude to “blame the victim”.

Mono-Causal accident proneness approach

• This approach argues that the accident-prone drivers should be identified and kept away from traffic, or force them to improve.


• Since all attempts to identify these drivers in advance have failed, this approach was not successful.

Mono-Causal chance phenomenon approach

• This approach considers crashes as completely a matter of chance, so it was argued that they can not prevented.

• This approach concentrate on the consequences of the crashes

• e.g. crashworthy cars, frangible poles

• There are some positive points about this approach• e.g. driver skill, behavior and post crash countermeasures.


Multi_Causal chance phenomenon approach

• By using scientific research and analysis, this approach argues that crashes are the result of chain of events.

• Prevention or reduction of the end result was depend on finding the weak link in the chain.

• Several interdependent factors such as human, vehicle and road and the interaction between these factors were partly deterministic and therefore controllable, and partly stochastic (random).

• This approach needs an extensive crash database and sophisticated statistical techniques to determine the interaction among the factors.


• Effectiveness and setting priorities became the leading principles for the management of road trauma and resulted in targeted speed enforcement, concentration on at risk group (young, alcohol impaired), and “accident black spot programs”.

• This approach led to great advances, and essentially is the state of the current practice.

Multi-Causal static system approach

• This approach emphasizes the nature of the problem.


• It is based on a problem-oriented strategy of choosing a particular part of the problem and bring resources to examine it more closely.

• The goal of this approach is to gather as much data as possible about not only the site and circumstances of the crash, but background information and circumstances before the crash.

Multi-Causal dynamic system approach

• This approach argues that in every crash the probability of failure is partly the results of actions or circumstances which preceded them.


• The goal of this approach is to analyze the dynamic characters of the crash process by series of snapshots captured by in-depth data.

• This approach is not only problem-oriented. It focuses on effectiveness, but also aims at optimizing and integrating the data.

In summary, significant progress in tackling roadtrauma was achieved when we moved from mono-causalto multi-causal approaches, since the simple approachesoverlook the interaction between the road user, the vehicle and the road system.

Road Safety StrategyTrinca et al (1988) summarized road safetystrategies in five categories.

Exposure Control

• Improving the safety by reducing the amount of travel, or substituting safer forms of transportation.

• Vehicle restriction

• This strategy is in conflict with some other values in society such as freedom of movement, freedom of where to live and work.

Road Safety Strategy (Cont.)

Some specific program options

• Alternative to road transportation• e.g. rail, bus, air, telecommunity

• Vehicle restrictions

• Roadway restrictions• e.g. truck bans in local streets

• User restrictions

• e.g. driver license age, curfews for novice drivers, limits on blood alcohol level, graduated licensing.


Crash Prevention

• Crashes possibly can be prevented or more likely reduced by better engineering actions.

• Road engineering can have an important effect on safety.

• A modern freeway can be about 10 times safer per vehicle mile than an undivided 2-lane road.

• Road design, construction, maintenance and management all can improve safety.

• Safety benefits are about 15 percent of the total benefits of an urban road project and 5 percent of the benefits of a rural road.


• Safety benefits are often considerable since they can outweigh costs by 4 or 5 to one.

• Safety should be an important input to these road decisions:

• Design• Construction standards• Operation

• Vehicle engineering in relation to both a vehicle’s initial design and it’s in-service condition can affect safety.

• Vehicle engineering to improve safety includes:• Braking• Lights, reflectors• Handling• Driver controls


• Visibility• Crashworthiness• Heating and ventilation• Stability

Behavior Modification

• Although many resources are devoted to various programs to improve behavior , the cost-effectiveness of behavior modification as a safety measure is unproven.

• Typical programs related to behavior modification include:• Pedestrians training (seems to be effective)• Driver training (not highly effective in producing safer drivers)• Enforcement (most effect on driver’s behavior if they perceive a

probability of being detected).


Injury Control

• This is relatively a new development. It is based on the fact that deaths and injuries can be reduced if conditions during the crash phase are modified.

• Programs relating to vehicle and the road are:• Cars

• Seat belt restraint• Anti burst door locks• Cabin structural integrity• Laminated glazing (safety glass)• Energy absorbing steering columns• Head restraints• Forgiving interior fittings


• Bicycles and motor cycles• Helmets

• Buses• Seat belts• Forgiving interior fittings

• Road environment

Post injury management• Post crash involves efficient treatment system to cope with

injured• Road deaths typically occur in three time periods

• In crash or promptly after it• Death in this period is the result of disruption to brain,

central nervous system, heart or major blood vessels.• Approximately 50% of deaths occur in this period, but it

occurs in only 5% of casualty crashes


• There is a little that medical science can do for this group

• Within the period of 1-2 hours after crash• Death is the result of major head, chest injury or major blood

loss• About 35% of deaths occur in this period from about 15% of

casualty crashes

• Within 30 days of hospital admission• Death is the result of brain death, organ failure and

infection• About 15% of deaths occur at this stage

Therefore the major impact of post-injury management is in 1-2 hour period after the crash. It is mainly dependentupon quick roadside and hospital emergency treatments


• Programs provided to improve this strategy are:

• Training of the care providers• Emergency medical personnel• First aid education for the public

• Training for hospital personnel• Effective communication to notify location and nature

of the crash• System to ensure rapid response• Effective and efficient transportation of injured to

hospitals• Establishment of specialized units at major hospitals

Road safety policy and programs

Management of the road safety is a majorchallenge, since it is a complex issue.

Each country has approached the road safetyproblem differently, and developed strategies toreduce road trauma and it’s costs.

In United Kingdom, the government in 1987 set atarget of reducing casualties from 320,000 to 220,000 by the year 2000, despite an expected 50percent increase in traffic.

Road safety policy and programs (Cont.)

Much of responsibilities to achieve this target was on the shoulders of local authorities, who produced a plan called “Road Safety Code of Good Practice” outlining the followingcomponents:

• Planning• Information• Engineering• Education and training• Enforcement• Encouragement• Coordination of resources


In Australia, the national strategy was to reduce road trauma during 1990’s with the road safety action taken by federal, state and local government.

The goal was to reduce road fatalities to 10 per 100,000 population by year 2001 with corresponding reduction in injuries.

To achieve this goal, a national action plan with following objectives developed:

• Major stakeholder ownership and involvement in road safety


• Road safety as a major public health issue• Road safety as a major economic strategy• Road safety as priority in management of transportation

and land use• Safer vehicles, roads and drivers• Integrated framework for road safety planning and action• Strategic research and development program


In the US, safety management systems (SMS) were required to be developed by October 1994 and fully operational by October 1996. (law since repealed)

The program areas that needed to be addressed in SMS were as follow:

• Coordinating and integrating broad based safety programs into comprehensive management approach

• Identifying hazardous safety problems and roadway locations, and come up with countermeasures to correct them.


• Ensuring early safety consideration in all transportation projects.

• Identifying safety needs of special road user groups in planning, design, construction and operation of the roadway system

• Older drivers• Novice drivers

• Routinely maintaining and updating safety hardware, highway elements and operational features.

Unlike the UK and Australia, the US did not set a specific target for road safety improvements (until later)

Documents

Ogden Chapter 1: Safety Management System. Road Safety Analysis The nature and extent of the road safety problem with regard to humanitarian, public health