Chapter 7: Site observations of traffic infrastructure
7.1 Introduction
This chapter will focus mainly on Road Safety Inspections (RSI). Some references to Road Safety Audits (RSA) will be made in order to expound the differences and similarities between RSI and RSA. It will be based on a literature review (general description and definitions) and some examples of the RSI/RSA.
Both RSI and RSA aim to reduce road accidents by analysing road infrastructure elements that could influence accident risk. These techniques allow the mapping of the risks of accidents across the entire European road network, which allows a comparison of the safety levels of roads across Europe. Within these techniques accident patterns on new and existing roads are studied. Additionally, the self-explaining and forgiving character of the roads are evaluated by assessing the crash-friendliness of the road infrastructure elements. In this respect, both techniques assist in reducing fatal and serious injuries among road users as it is highly recognised that the self-explaining and forgiving roads concepts assist in reducing injury severity. The difference between inspection and audit is related to the phase in which the infrastructure is found. RSI are performed if the road is already build and opened to traffic for a time period sufficient for accidents to have been registered. On the contrary, RSA are performed for roads in the preliminary stages before opening to traffic. This includes the phases from planning to construction (and also the first months with traffic). Therefore, one determinant that must be taken into account is that for RSI we have accidents to analyse, and for RSA we analyse only the infrastructure without accidents. The European Directive 2008/96/EC (European Parliament & European Council, 2008) defines an RSI as ‘an ordinary periodic assessment of a road’s features and deficiencies which from a road safety perspective make maintenance necessary’ (see section 7.2).
Road safety audits and inspections were introduced in road safety management by the European Traffic Safety Council on behalf of the European Commission. The council produced the report ‘Road Safety Audit and Safety Impact Assessment’ in 1997. The report focused on the benefits of RSA and recommended all Member States to introduce the tool. Before that, there had been a progressive shift in road safety management thinking and practices in high-income countries. Four main development phases for road safety management can be considered, progressively increasing the ambitions in terms of results (Peden et al., 2004):
The objective of this chapter is to identify the key elements that help to assess and treat the risk, focused on vulnerable road users (VRUs).
According to the World Road Association, RSA and RSI are proactive approaches that can be applied to avoid future accidents by (PIARC, 2015):
It is generally accepted that RSI are performed on existing roads, and RSA are performed during the design process. However, some countries refer to both analysis for similar processes
Figure 1: Sequence of road safety checks during the design stages (PIARC, 2011).
7.2 European Directive on road infrastructure safety management
The European Directive 2008/96/EC of the European Parliament and of the Council on Road Infrastructure Safety Management was issued on 19 November 2008 and represents a legal basis for RSI in the European Union (EU). This EU directive is compulsory for roads that are part of the trans-European road network (TEN). One of the reasons for issuing this directive was to ensure a high level of safety on the TEN, which is of fundamental importance for the integration and cohesion of the EU.
Road infrastructure is one of the policy areas for improving road safety and should contribute to the reduction of the number of collisions. The aim was to halve the number of road collision victims in the EU between 2001 and 2010. Establishing appropriate procedures is fundamental for improving road infrastructure safety.
In the EU directive, it is stated that some Member States already have road infrastructure safety management systems that work well. These countries are allowed to continue using the existing methods if they are in accordance with the aims of the directive.
The EU directive also says that the safety level of existing roads should be increased by investing financial resources in the road sections with the highest number of collisions and/or the highest collision reduction potential. Regular periodic safety inspections are an appropriate instrument for preventing possible dangers for all road users, including VRUs, and RSI are also applied to roadworks sites.
This EU directive defines four types of instruments which should help to improve road safety:
Within the Article ‘Safety Inspections’ it is stated in the directive that the Member States shall carry out safety inspections on existing roads in order to identify the road safety-related features and to prevent collisions. These inspections should be performed periodically and by a competent entity.
The Member States are encouraged to compose their own charts, which should demonstrate their adherence to the requirements within the directive, and to make them public. The Member States are also encouraged to apply this directive to other national roads which are not part of the TEN.
7.3 Basic concepts in RSA/RSI
RSA and RSI are procedures to test the safety level of the road infrastructure. The RSA test the design of new roads or the reconstruction of existing roads, whereas the RSI are implemented for testing existing roads. An RSA, therefore, aims to 'improve' the road safety before the road is built or reconstructed.
RSI can also contribute to road safety. An RSI can be carried out periodically on an entire network but also on road sections that have an above-average number of accidents. Various assessment methods are used in RSI, none of which have standardised procedures. For a more systematic use of RSI such standardisation is desirable. Little is known about the effects of an RSI.
Most practices agree on certain similar characteristics of RSI:
7.4 Actors in the RSA/RSI
A qualified team carries out the inspection or audit. This team must fulfil the following requirements (European Directive 2008/96/EC):
7.4.1 Skills
Experience in road safety engineering is the one essential ingredient in any road safety team. This should be linked to an understanding of
Different stages of audit require different skills and experience.
The most successful teams will be those able to use their skills to see the road project from the point of view of the different types of ‘customer’ or road user – those able to think and perceive like each user.
7.4.2 Experience
Members with adequate road safety engineering experience should form the auditor team. There should be one team leader with road safety experience and training, named the Senior Road Safety Auditor.
A Senior Road Safety Auditor has:
An organisation that does not have the necessary skills and experience for road safety audits can import those skills for specific projects and use these opportunities to train its own staff.
7.4.3 Independence and subjectivity
The road safety auditor must be independent, so that the design is viewed with ‘fresh eyes’. Nonetheless, good communication between the parties must be established and maintained if the audit is to be done effectively and without wasted time and effort.
Further, the sensitivity associated with having design work ‘judged’ should be recognised.
Auditors need to be objective in their assessments and consider all road users (pedestrians, bicyclists, public transport users, powered two-wheeler drivers, truck and bus drivers, etc.). They have to avoid just analysing the roads from the car-driver perspective. Designers and clients need to consider audit recommendations objectively and gain from the experience.
7.4.4 Number of auditors
It is advisable to have a road safety audit team of two or more experienced and qualified professionals. The benefits of having a multi-member audit team, rather than a single person, include
It may not always be practical to have a multi-member team conducting an audit. An audit of a low-budget project could consist of phone calls, an examination of a single plan, a site inspection during the day and during the night and a short report.
7.5 A step-by-step guide for inspections and audits
A road safety audit or inspection is a relatively straightforward process. The steps in the process are illustrated in the flow chart in Figure 2. In some organisational structures, and for some minor projects, some of the steps may be brief, but the sequence of steps will still apply. The steps apply equally to design-stage audits and other audits.
Figure 2: Audit process (based on European Parliament & European Council, 2008).
The details in each step of the flow chart should be adapted to suit the nature and scale of a particular project. For example, an audit of a small-scale, single-site project may involve a phone call rather than a commencement meeting, documentation may consist of a few pages of information and a single plan and the report may be as short as one or two pages if there are no significant problems.
At the other end of the scale, a road safety audit of a major road design project is likely to involve meetings, a large number of plans and a report of several pages.
Responsibility for the planning, design and construction of the project remains with the project manager and the implementation team. It is not the role of the road safety auditor to take over or redesign the project. The role of the auditor is to provide independent advice in the form of written recommendations. This advice is then considered by the designer and/or the client (depending on who engaged the auditor), and a formal decision is made by them on whether or not to adopt each of the recommended safety alterations.
7.5.1 Preparation work in the office
Basic material
Basic material is here meant to include the documents and data necessary to carry out the inspection.
All relevant information must be provided to the inspection team. The project designer should collect all the necessary and relevant information in a usable form for the inspection team. Information will include scheme reports, accident and traffic data, drawings and relevant sections of contract documents. This step may need to be initiated well before it is time to engage the road safety audit team. It may be necessary to collect additional information, such as traffic volumes. This should be considered early enough to avoid delays. The inspection team also needs to be given a clear understanding of what tasks are to be included in the assessment.
Information to be provided to the inspection team will typically include the following:
a. A clear statement of the expected outcome from the audit
This may require a written report or a simple reference to the procedures and optional audit report formats in these guidelines.
b. Project intent
This concisely sets out the purpose of the project (i.e. the design project, not the audit), how any deficiencies will be addressed, any design compromises that have been made and the reasons and any community input from prior discussion, correspondence and consultations. For large projects, some of this information may be in reports used to support earlier funding or programming decisions.
c. Site data
d. Plans and drawings
Simple accident study
Once the inspection team has the basic material, it is important to study the registered accidents.
When considering the accident situation on a road section, it is important to think proactively, that is, not just focusing on what has happened but also on anticipating what can happen in the future.
One should be focused on previous accidents on the road section in order to identify the hazard points in the road. Inspectors should also gain a rough overview of the accident situation along the section. Past occurrences give as information about the actual road situation, but inspectors should not overlook other hazardous conditions that may affect general road safety.
It is the general accident picture of the section that should be focused on but always based on the locations where the individual accidents have occurred. This is achieved through a simple accident study. Which accident types dominated on the section and which have resulted in serious injury should be revealed. Moreover, it would be appropriate to check if there are other factors that typify the accident picture, such as the time of the year, time of the day, etc.
The accident study must reveal the type of road users that were injured in the section. In this respect, inspectors must know if there is any safety problem regarding VRUs.
Inspectors should also look at the previous black-spot reports and check if there is any black-spot or zone in the analysed road section.
It is recommended to carry out the accident study before the inspection is completed and to check whether the accident picture confirms the hazard locations in the road section.
7.5.2 On-site field study
It is essential for the road safety inspection team to visit the site in daylight to identify any problems relating to the present configuration and, if appropriate, to visualise the future proposals and their effects. In addition, it is a good practice to visit the road at night-time. Aspects related to luminosity and reflectivity can be better analysed without daylight. The audit team should carefully select the most effective periods to inspect the site as traffic conditions can vary throughout the day or week.
A night-time inspection is also essential except where, in the experience of the client, there will be nothing additional to observe. However, these circumstances should be rare. The visual information available to road users can be markedly different at night-time, and it can be surprising what additional issues can be identified on a night-time inspection, even where work has not yet commenced.
When the audit team is on site, they must look beyond the limits of the design plans (or the limits of works at the pre-opening stage): the inspection should include the adjacent road sections.
Transition or terminal zones, where the new (and usually higher standard) road transitions into the existing road system can often be locations of greater hazard as
In addition, new roads or new traffic arrangements can often disrupt existing traffic and pedestrian movement patterns.
The inspection should be undertaken from the point of view of all the likely road user groups and not just motorists. Young and elderly pedestrians, truck drivers, cyclists, elderly and disabled drivers have quite different safety needs.
Consider how well the design caters for the different types of movements, such as crossing the road and entering the traffic stream or leaving it as well as for travelling along the road. Consider these for the different user groups and the effects of different weather conditions.
Taking photographs or videotapes allows for later reference and possible inclusion in the report, but such materials must not be used as a substitute for a site inspection: all audit team members should inspect the site.
7.5.3 RSI report writing
The main task of the road safety inspection report is to succinctly report on aspects of the project that involve hazards and to make recommendations about corrective actions. The recommendations will usually indicate the nature or direction of a solution rather than precise details. Responsibility for the latter will rest with the designer. The report provides the formal documentation on which decisions about corrective action will be based.
A positive element of the design that improves safety can be mentioned in a road safety audit or inspection report, but it is not necessary to mention them. The purpose of the report is not to rate the design but rather to address any road safety concerns.
In some cases, safety concerns may be identified, but a recommendation, even a broadly directive one, may not come to mind. In this case the safety issue should not be ignored: simply record the finding (i.e. the safety concern), and under ‘Recommendation’ write ‘Investigate treatment and implement it’ or something similar.
In what order should items be listed? Sequentially along the length of a project? In the order in the checklists? Grouped by common issues? There is no single best way of ordering findings and recommendations, but the most important consideration is that the order be logical and helpful for the report’s recipients when they consider the corrective actions. For example, where there are three distinct intersections and ramps at a grade separated interchange, and each one has identified problems with the four elements of alignment, cross section, delineation and visibility, it may be better to discuss each site in turn rather than discuss each design element about the different sites in turn. In this way, any possible interactions between the problems at each site are more likely to be recognised and addressed effectively. On long road projects, it may be more appropriate to split the project into sections. In any event, if there is any concern that mutually dependent recommendations are separated in the report, they should be cross-referenced.