Traffic safety

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The term traffic safety refers to the risk of a person being killed or seriously injured while using the traffic network as a pedestrian, cyclist or user of public or private transport.

The importance of traffic safety

The importance of traffic safety is obvious; traffic accounts for many deaths and injuries. According to the World Health Organization, road traffic injuries caused an estimated 1.26 million deaths worldwide in the year 2000. The average rate was 20.8 per 100,000 people, 30.8 for males, 11.0 for females [1]. Measures can be taken in order to reduce the number of casualties and injuries greatly.

How to improve traffic safety

Safety can be improved by reducing the chances of a driver making an error, or by designing vehicles to reduce the severity of crashes that do occur[2] (vehicle safety).

It is potentially easier to inflict damage to a situation with a low traffic safety. Therefore (and also for security issues) it is important to create preconditions for a high traffic safety situation. This can be done in two ways, firstly to create a safe road network, and secondly to use safe vehicles. The urban planner can help to create a safe road network, however, has no influence on the safety of vehicles.

Vulnerable road users safety

Safety of vulnerable road users concerns safety of cyclists and pedestrians. A group of road users can be defined as ‘vulnerable’ in a number of ways, such as by the amount of protection in traffic (e.g. pedestrians and cyclists) or by the amount of task capability (e.g. the young and the elderly). Vulnerable road users do not usually have a protective 'shell', and also the difference in mass between the colliding opponents is often an important factor. Vulnerable road users can be spared by limiting the driving speed of motorized vehicles and separating unequal road user types as much as possible. Adapting motor vehicles (e.g. by side-underrun-protection for trucks and collision-friendly car fronts) can lessen the injury severity of vulnerable road users. In crashes involving only vulnerable road users and no other road users, it is mainly the infrastructure that is important for the prevention and limitation of injury [3].

Other preventive measures that are often taken or recommended are wearing a helmet (cyclists), infrastructure adaptations such as pedestrian crossings, separate bicycle lanes etc. Recent developments include safety systems in cars such as collision avoidance systems, night vision and the bicycle airbag.

Road safety

Best practice road safety strategies focus upon the prevention of serious injury and death crashes in spite of human fallibility (which is contrasted with the old road safety paradigm of simply reducing crashes assuming road user compliance with traffic regulations). Safe road design is now about providing a road environment which ensures vehicle speeds will be within the human tolerances for serious injury and death wherever conflict points exist[4].The two internationally most well-known ˜safe system approaches" are the Swedish "Vision Zero" and the Dutch program "Duurzaam Veilig", or 'Sustainable Safety' in English[5].

Over the years, the Sustainable Safety vision has become a household concept, not only in the Netherlands but also internationally. The Sustainable Safety vision was updated in 2005 and published in Advancing Sustainable Safety. The five principles of Sustainable Safety are the essence of sustainably safe traffic, and are summarized in the table below:

Table 1: Principles of the Dutch program Sustainable Safety[6]

Sustainable Safety Principle Description
Functionality of roads Mono-functionality of roads as either through roads, distributor roads, or access roads in a hierarchically structured road network
Homogeneity of mass and/or speed and direction Equality of speed, direction, and mass at moderate and high speeds
Predictability of road course and road user behaviour by a recognizable road design Road environment and road user behaviour that support road user expectations through consistency and continuity of road design
Forgivingness of the environment and of road users Injury limitation through a forgiving road environment and anticipation of road user behaviour
State awareness by the road user Ability to assess one's capacity to handle the driving task

An entire website is devoted to this version of Sustainable Safety[7]. On this website you can find the integral version of the book, the brochure containing a summary, and all kinds of background information.

Vehicle safety

Most industrialized countries have comprehensive requirements and specifications for safety-related vehicle devices, systems, design, and construction. These may include[8]:* Passenger restraints such as seat belts — often in conjunction with laws requiring their use — and airbags* Crash avoidance equipment such as lights and reflectors* Driver assistance systems such as Electronic Stability Control* Crash survivability design including fire-retardant interior materials, standards for fuel system integrity, and the use of safety glass* Sobriety detectors: These interlocks prevent the ignition key from working if the driver breathes into one and it detects significant quantities of alcohol. They have been used by some commercial transport companies, or suggested for use with persistent drunk-driving offenders on a voluntary basis

Footnotes and references