Road safety audit
Encyclopedia
A Road Safety Auditis defined as "the formal safety performance examination of an existing or future road or intersection by an independent, multidisciplinary team. It qualitatively estimates and reports on potential road safety issues and identifies opportunities for improvements in safety for all road users."
Road safety audits are commonly used in the United Kingdom and Australia, and are coming into wider use in the United States. They are a mandatory requirement for all trunk road Highway Improvement Schemes in the UK (including motorways). The requirements of a Road Safety Audit are contained in the Design Manual for Roads and Bridges
Volume 5 Section 2 - 'HD19/03 Road Safety Audit'
A key feature of a road safety audit is the use of a team of professionals with varied expertise. The team should include highway safety engineers, highway design engineers, maintenance personnel, and law enforcement. Additional specialties should be added to the team as needed. The team members must not be involved in the design or maintenance of the facility being examined, so that they can have an objective point of view.
The road safety audit may investigate general safety conditions, or it may focus on specific concerns or users. Walkability audits concentrate on pedestrian safety and accommodation , and transit audits focus on safety of bus and train users. The New York State Department of Transportation
's Safety Appurtenance Program (SAFETAP) uses audit techniques to make simple but effective safety improvements in conjunction with road resurfacing projects. . This helps prevent increases in crashes that sometimes occur due to increased driving speeds after road resurfacing.
Audits attempt to avoid some of the limitations inherent to any crash history scoring system. Some of these limitations are:
If historical crash data are available, the audit team should make use of them. However, one of the strengths of the audit process is it can find safety concerns before they contribute to crashes. Lack of data is a reason to use the audit process, rather than an excuse not to.
Road safety audits are commonly used in the United Kingdom and Australia, and are coming into wider use in the United States. They are a mandatory requirement for all trunk road Highway Improvement Schemes in the UK (including motorways). The requirements of a Road Safety Audit are contained in the Design Manual for Roads and Bridges
Design Manual for Roads and Bridges
The Design Manual for Roads and Bridges is a series of 15 volumes that provide official standards, advice notes and other documents relating to the design, assessment and operation of trunk roads, including motorways in the United Kingdom, and, with some amendments, the Republic of Ireland .They...
Volume 5 Section 2 - 'HD19/03 Road Safety Audit'
A key feature of a road safety audit is the use of a team of professionals with varied expertise. The team should include highway safety engineers, highway design engineers, maintenance personnel, and law enforcement. Additional specialties should be added to the team as needed. The team members must not be involved in the design or maintenance of the facility being examined, so that they can have an objective point of view.
The road safety audit may investigate general safety conditions, or it may focus on specific concerns or users. Walkability audits concentrate on pedestrian safety and accommodation , and transit audits focus on safety of bus and train users. The New York State Department of Transportation
New York State Department of Transportation
The New York State Department of Transportation is responsible for the development and operation of highways, railroads, mass transit systems, ports, waterways and aviation facilities in the U.S...
's Safety Appurtenance Program (SAFETAP) uses audit techniques to make simple but effective safety improvements in conjunction with road resurfacing projects. . This helps prevent increases in crashes that sometimes occur due to increased driving speeds after road resurfacing.
Audits attempt to avoid some of the limitations inherent to any crash history scoring system. Some of these limitations are:
- Reactive systems require waiting until crashes have already occurred, possibly with resulting injuries and fatalities.
- Crash frequencies are subject to regression toward the meanRegression toward the meanIn statistics, regression toward the mean is the phenomenon that if a variable is extreme on its first measurement, it will tend to be closer to the average on a second measurement, and—a fact that may superficially seem paradoxical—if it is extreme on a second measurement, will tend...
. It can be hard to determine whether good or poor short-term safety performance is due to the inherent safety or hazards of the site, or random variation. Sites with high or low crash rates are likely to move towards the mean as a matter of course, even if nothing changes. - Most existing procedures focus on sites that have experienced the most accidents, which may or may not be the sites that could benefit most from a safety improvement.
- Reactive systems are limited by the quality and timeliness of the data entered into them. Deficiencies in crash reporting limit the effectiveness of these systems.
If historical crash data are available, the audit team should make use of them. However, one of the strengths of the audit process is it can find safety concerns before they contribute to crashes. Lack of data is a reason to use the audit process, rather than an excuse not to.