10.2 PROGRAMME-LEVEL AND PROJECT- LEVEL APPROACHES

Road agencies typically allocate funding to improve high-risk locations, whether based on crash history or on the potential risk. This funding may take the form of dedicated funding for high-risk locations and/or be embedded in other operating budgets (for example, major projects or asset management). Most actions undertaken by a road agency have a safety impact, whether they are initiated for safety reasons or not. If consideration of safety is included in all decision-making, safety risk can be reduced, often at little or no additional cost. The assessment of risk needs to occur at the programme and project level, and the advice provided in this chapter is relevant to both.

The first difficulty encountered in implementing such a program is of a methodological nature. It consists in knowing how to identify dangerous sites. Objective identification methods that may be used by road administrations are summarized in the following diagram, extracted from Figure 10.19.

Social demand for road safety improvements can be expressed in four different ways, based on the nature of the hazard considered:

• Proven hazard (objective safety): measured objectively, based on crash statistics.
• Potential hazard (objective safety): scientifically assessed by measuring crash risk in relation to road characteristics and traffic levels.
• Experienced hazard (subjective safety): expressed subjectively by users, most often with a major deviation from proven or potential hazard.
• Intolerable hazard (subjective safety): types of crashes that are considered intolerable by society, even: e.g. crashes involving children, a vehicle crossing a freeway median.

There may be significant gaps between objective safety and subjective safety (also called ‘security’ - Figure 10.3). For example, Hauer (1997) explains that while marked crossings are perceived by road users as a safety improvement, they have been shown to be detrimental to safety (based on Herms, 1972).

Treatment of proven hazards and potential hazards (objective safety) uses the following scientific, rational methods:

• Crash data collection and processing.
• Objective identification methods:
  • based on data,
  • based on observations.

Treatment of experienced hazard or intolerable hazard (subjective safety) should be based on communication and information, in order to explain to road users and residents the consequences of actions they may have suggested. The following actions should be taken:

• Provide objective figures on crashes or risk and compare them with other situations.
• Explain advantages and disadvantages of solutions spontaneously suggested by users.

Various types of safety indicators may be used to detect and classify road hazards. These are discussed in more detail under Criteria for Selecting Locations to Investigate for Treatment.

Assessment of risk should be undertaken for the entire road network for which the road agency is responsible, based upon proven or objective hazard assessment. Such an approach would require a network-wide assessment of risks and issues. The outcomes of such an approach would identify key crash types, trends, geographic regions or areas, deficiency types, etc., with the outcomes of this assessment informing programmes of work.

It is often the case that a small percentage of roads account for a large percentage of deaths and serious injuries. At the programme-level, the task is to identify such routes and address these. For those countries with limited resources or that lack adequate data across the whole network, such locations are the most important to assess. These locations can form the basis of a corridor demonstration project. The content from this and the following chapters can be used as a guide to the assessment of risk across networks or along corridors. The examples shown in the case studies below provide information on the corridor approach in Belize and in New South Wales, Australia.

At a project level, the steps outlined in this chapter are equally relevant. They highlight how to identify risk at more specific locations (e.g. intersections, routes or areas) and diagnose risk at these locations. Crash-based (reactive) and more proactive approaches are relevant to both programme and project level approaches. In each case, whether programme or project level the same steps are involved in assessing risks and identifying casual issues. The Moldova used iRAP to assess risk, and the Czech Republic’s IDEKO research project developed method and tools for the treatment of hazardous locations.