The objective of SafetyCube is to develop an innovative road safety Decision Support System (DSS) that will enable policy-makers and stakeholders to select and implement the most appropriate strategies, measures and cost-effective approaches to reduce casualties of all road user types and all severities.
At the core of the project will be a novel and comprehensive analysis of accident causation factors combined with newly estimated data on the effectiveness and cost-effectiveness of safety measures, not just in relation to reduction of fatalities but also the number of injured. An operational framework will be established to provide future access to the DSS once the project is completed.
The project has four sub-objectives:
- To develop new analysis methods for (a) Priority setting, (b) Evaluating the effectiveness of measures (c) Monitoring serious injuries and assessing their socio-economic costs (d) Cost-benefit analysis taking account of human and material costs
- To apply these methods to safety data to identify the key accident causation mechanisms, risk factors and the most cost- effective measures for fatally and seriously injured casualties
- To develop an operational framework to ensure the project facilities can be accessed and updated beyond the completion of SafetyCube
- To enhance the European Road Safety Observatory and work with road safety stakeholders to ensure the results of the project can be implemented as widely as possible
SafetyCube will prepare the organisational and conceptual framework and technical content for the road safety Decision Support System. The approach focusses on these two areas with the preparation of the DSS operational framework taking place in parallel with the development of the evaluation of accident causation risks and measures.
While there is a general agreement that measures should be selected and evaluated on the basis of objective criteria, in practice evaluation studies are few and differing widely. The big challenge is to describe a procedure that is methodologically sound as well as practically feasible. To be able to decide between measures of different types, the method’s intermediate steps have to be flexible to adapt to different types of data and estimation methods while the outcomes still have to be comparable. To use scarce resources wisely, the effectiveness of measures has to be related to their costs.
The methodology deployed to evaluate the accident causation risk factors and measures will be central to the project and will be applied to road, vehicle and behaviour factors in a consistent manner. Due to the important place this methodology plays at the centre of the project it is presented in some detail below.
Step 1: Identification of risk factors
The purpose of identifying risk factors is to provide a basis for selecting the most important road safety problems for treatment. The term risk factor denotes any factor that contributes to accidents or injuries. There are risk factors related to all elements of the road system and the interactions between these elements. The following methodological guidelines are proposed for identifying important risk factors and will be considered in WP 3:
- Start with making lists of the risk factors whose contributions are to be estimated. The following risk factors should always be included, because they are likely to be important in all countries: speeding, driving under the influence or alcohol or drugs, non-use of protective devices (belts, helmets, etc), lower level driver errors, mass-incompatibility between vehicles, complexity of urban traffic environments, vulnerability of unprotected road users in mixed traffic, risk factors related to the environment (darkness, bad weather, etc), road design and maintenance deficits (on the basis of self-explaining and forgiving roads design principles etc)
- Assess the importance of risk factors. An analysis of important risk factors should aim for quantifying the contributions of the 10-20 most important ones. The importance of a risk factor is best stated in terms of its population attributable risk, that is in terms of the prevalence of the factor and the strength of its association with accidents and/or injuries.
- The correlations between risk factors should be assessed in order to avoid double counting the potential for improving road safety by eliminating a certain risk factor.
- The amenability of risk factors to treatment should be assessed. Not all risk factors are easy to remove or bring under control.
Step 2: Identification and estimation of the effects of road safety measures
The first step should be to conduct a broad survey of potentially effective road safety measures should be conducted. Therefore an exhaustive list of measures will be made by WPs 4, 5 & 6. Basic information, such as a description of the measure, a rough estimate of safety effects (high / low, or a range of known values), costs (high / low, or a range of known values) will be collected for all measures. A road safety measure is regarded as potentially effective if either (a) it has been found in evaluation studies to be effective or, (b) it favourably influences risk factors that are known to contribute to accidents or injuries. Preliminary guidelines for identifying road safety measures are:
- Start with an initial survey to make an inventory of all measures that are effective or potentially effective. The term potentially effective refers mainly to new measures that have still not been widely applied in traffic, but could improve road safety, e.g. Intelligent Speed Adaptation (ISA).
- Assess the extent to which the measures have already been implemented. Measures that have been fully implemented in all countries should be given low priority, as they no longer have much potential for further improving road safety.
- Assess the extent to which different road safety measures address the same problem. If there is considerable overlap between a pair of measures, this should be taken into account when estimating the effects of the measures (see below).
- Classify measures with respect to whether their effects are sufficiently well-known to be numerically estimated or not. Measures whose effects cannot be estimated numerically should not be included in the subsequent stages of analysis.
A number of national and international sources provide numerical estimates of the safety effects of road safety measures. These sources should be surveyed. When assessing the applicability of estimates of effect one should consider the following issues:
- Is there evidence that effects of road safety measures vary systematically over time or between countries?
- Do the effects of road safety measures vary systematically along other dimensions (than time and space)?
- What is the quality of the evaluation studies that form the basis of estimates of effect?
The use of estimates of the effects of road safety measures must to some extent rely on the principle of insufficient reason: estimates are used unless there are reasons for not using them. Thus, for example, if the effects of road lighting have been evaluated in many countries during a long period, and the results have been consistent, there is no reason to believe that effects would be totally different in a country where no evaluation studies have been reported. However, this is not to say that one should uncritically apply estimates of effect as reported in the literature. The following guidelines are provided for use of evaluation studies to estimate the effects of road safety measures:
- When evaluation studies have been summarised by means of meta-analysis, ascertain whether this analysis indicates that there is systematic variation in effects. If not, summary estimates of effect can be applied as published. If there is systematic variation in estimates of effect, consider whether this variation can be modelled by means of an accident modification function.
- When results of several evaluation studies are available, but no meta-analysis has been made, consider summarising results by means of meta-analysis. If a full meta-analysis is not feasible, exploratory techniques such as stem-and-leaf plots can be used.
- When developing an accident modification function, select studies that employed the same study design (e.g. before-and-after studies) and are as homogeneous as possible with respect to study quality.
Step 3: Estimation of costs of measures
To perform cost-benefit analyses, the costs of implementing road safety measures must be estimated. Costs of measures may be direct or indirect. Direct costs are the out-of-pocket payments made to implement a measure. Indirect costs are loss of benefit associated with a measure that influences travel demand. For some road safety measures, the direct costs are small and the indirect costs large. As an example, the direct costs of withdrawing a driving license for health reasons are small, but the indirect costs in terms of lost opportunities for travel can be large, but are usually difficult to estimate very precisely.
How to estimate costs of measures also depends on who is paying the measures and the nature of the costs. With respect to who pays, public expenditures must be treated differently from private expenditures. The social cost of public expenditures funded by means of taxes should include an adjustment factor representing the distortionary effects of taxes. This factor is usually included by adjusting public expenditures upward by a certain factor. Thus, a public expenditure of 1 million may represent a social cost of 1.2 million. A similar adjustment factor should not be applied to private expenditures.
A final problem in estimating the costs of road safety measures concerns difficulties in identifying the costs of specific safety components in cars, such as electronic stability control. Consultation with the vehicle industry will be made in order to identify the costs of safety components as precisely as possible.
SafetyCube will utilise data from Government and industry stakeholders to estimate the costs of introducing and operating safety measures. The common methodological basis developed within the project will enable costs to be compared across the vehicle, road and behavioural areas. The guidelines developed within the project will also include practical approaches to handle commercially sensitive information from safety system manufacturers.
Step 4: Enabling priority setting between road safety measures – cost-benefit analysis
Once the effects of several road safety measures have been estimated, the next task is to determine ways for the priority to be given to the various road safety measures. This can be done according to many criteria, as illustrated below.
- Rank order measures according to the number of fatalities and serious injuries they prevent. Setting priorities according to such a ranking is consistent with Vision Zero or similar long-term ideals for transport safety, aiming for the elimination of fatalities and serious injuries.
- Rank order measures according to cost-effectiveness. Cost-effectiveness is the number of fatalities or injuries prevented per unit of cost for implementing the measures. It is important to note that cost-effectiveness may not be uniquely determined for each measure, in particular if its effects differ with respect to injury severity. A measure might then, for example, be ranked third according to cost-effectiveness in preventing fatalities and sixth in terms of cost-effectiveness in preventing serious injuries. To avoid this problem, one might convert effects referring to different levels of injury severity to a common scale, for example quality-adjusted life-years (QALYs). Moreover, to avoid the problem of different rankings with respect to different accident outcomes, injuries can be converted to years lived in disability (YLD) and combined to a common scale with fatalities (QALYs).
- Rank order measures according to their cost-utility. Utility is represented by means of a scale for quality of life, converting all effects to a QALY-metric. One should, however, be aware of the fact that there are many techniques for obtaining QALYs and that these do not produce identical results.
- Rank order measures according to net cost-effectiveness. The difference between cost-effectiveness and net cost-effectiveness is that in net cost-effectiveness, the costs of implementing a road safety measure have been adjusted to account for its non-safety impacts. This essentially amounts to a cost-benefit analysis in which all impacts, except for safety impacts, have been converted to monetary terms. This means that net costs may actually be negative, if, for example, mobility benefits alone are greater than the costs of implementing a measure.
- Rank order measures according to net present value. This is the main decision rule in cost-benefit analysis. Net present value is the present value of benefits minus the present value of costs. All impacts have then been converted to monetary values. A cost-benefit analysis includes all impacts of a measure, not just safety impacts.
It should be stressed that both QALYs and monetary values of safety are associated with large uncertainty. Moreover, when cost-benefit analyses are made in many countries, a complex issue is whether national figures for costs and benefits should be used or whether international average values should be used.
SafetyCube will consider the pros and cons of these different ranking methods and will make recommendations on when particular approaches should be applied.
WP1. Project management (WP Leader: LOUGH)
WP1 deals with the overall coordination of the project and the administrative work required for monitoring the progress of the project.
WP2. Dissemination and Stakeholder Consultation (WP Leader: CHALMERS)
WP2 aims to create an efficient network of stakeholders, including primarily the EC High Level Group on road safety, the CARE-expert group, the road and vehicle industry, but also associations of road users, road safety institutes, traffic police, insurance companies, the health sector, urban planners, public and goods transportation operators and other relevant road safety groups and associations both at European and at Member States level.
The stakeholder’s consultation has the following objectives:
- at the beginning of the project, to identify user needs for the European road safety Decision Support System – DSS (WP8), as well as “hot topics” to be examined within the project; candidate “hot topics” will be brought to WP8 for agreement.
- throughout the project, to provide data, knowledge and experiences, and assist in identifying road accident risk factors, and the project’s research priorities in implementation of related measures,
- to disseminate project (intermediate) results as soon as available until the end of the project and beyond.
Mechanisms for stakeholder involvement include workshops, web based and online channels, personal contacts and surveys. A “user needs” workshop will be organised at the beginning of the project, as well as a final conference at the end. Midterm, a series of thematic workshops will take place to get feedback on first SafetyCube findings and evidence based policy-making and thus maximise the potential impact on the 2020 casualty reduction target.
WP3. Development and validation of the methodological framework (WP Leader: BRSI)
WP3 aims to develop a common methodological framework for:
- the identification of risk factors in accident analysis
- the estimation of safety effects and cost-benefit analysis of road safety measures
- the estimation of costs of accidents and measures (also in relation with WP7)
- the use of core data for analyses
These methods will be used in WPs 4, 5 and 6. Preliminary results feed back into WP3 for further development and fine-tuning of the methods. The final methods, including instructions for use, will be available through the policy decision support system developed in WP8.
WP 4. Road user behaviour analysis (WP Leader: KFV)
WP 5. Infrastructure safety analysis (WP Leader: NTUA)
WP 6. Vehicle safety analysis (WP Leader: LAB)
These Work Packages will collect and analyse available data (macroscopic or in-depth) and knowledge (existing studies) for each of the three policy areas of road safety systems: road user (enforcement and training), infrastructure (design and operation), and vehicle safety (active, passive and tertiary safety). On the basis of the methodological framework created in WP3, each of them will :
- identify risk factors in accident and injury causation,
- estimate safety effects for road safety measures,
- estimate the effectiveness and cost-benefit of road safety measures,
The use of the comparable methods generated in WP 3 and the needs of the coordinated research strategy means that the same basic approach will be used in WP 4 – 6 with the same basic types of deliverables and milestones. More specifically, these WPs will each start with the creation of an exhaustive list of risk factors and road safety measures, for which a set of basic pieces of information will be available (i.e. description, known safety effects and costs, or expert ratings etc.). The stakeholders’ consultation taking place in WP2 will be an additional source of basic information on the risk factors and measures, as some of the elements at this stage may be described on the basis of expert opinion, national experiences etc.
This exhaustive list will be examined together with WP8, in order to make a selection of key issues in terms of both risk factors and measures that will be analysed and evaluated. For the selected measures, the methodologies and guidelines developed in WP3 will be implemented and tested. At the same time, care will be taken – under the coordination of WP8 – that the conceptual framework of the analyses is consistent with the “systems” approach, that the combined effect of measures related to more than one component of the system (user, infrastructure, vehicle) is taken into account etc. More specifically, WP8 assigns risk factors and related measures to the relevant WPs 4-5-6, will monitor the implementation of the analyses, will ensure that the system requirements are met, and will provide feedback on the analyses and the results.
Therefore, there is a continuous interaction between each of these WPs and with WP3 and WP8. They also provide essential input to WP2. A synthesis of the final results in each of the WPs will feed into WP8 to be integrated in the European policy decision support system.
WP7. Serious road injuries, analysis and strategy (WP Leader: SWOV)
SafetyCube addresses the special importance of the EC policy focus on serious injuries by dedicating WP7 to the analysis of serious road injuries, their health impacts and social costs and key risk factors that are relevant for serious road injuries, with the following main objectives:
- Assess and improve the estimation of the numbers of serious road injuries
- Determine and quantify health impacts of serious road injuries
- Estimate economic and human costs related to serious road injuries
- Identify key priorities for reducing serious injuries and limiting their health impact
The estimated costs related to serious road injuries are input for WP3 and the key risk factors are input for WP4 to 6 where measures will be proposed to deal with the identified risk factors.
WP8. European road safety policy Decision Support System (WP Leader: LOUGH)
WP8 concerns the final outputs of SafetyCube. It will create a user-friendly European road safety policy Decision Support System (DSS) and fill it with the main results of the project. The data and knowledge contents developed in the SafetyCube DSS will be integrated in the current European Road Safety Observatory. The project will use the hot topics to help develop and validate the System as well as directly providing useful decision resources to road safety stakeholders. In doing so, it will explicitly take account of the stakeholders’ needs and “hot topics” as identified in the various stages of WP2 and develop a business plan to enable the DSS to continue to operate after the period of the project to be able to accommodate results for future analyses and new measures. To meet the needs of stakeholders established in WP 2 a range of training material in support of evidence based methods will be prepared. The dissemination workshops will be used to validate the courses and support the stakeholders.
WP8 will also coordinate and monitor the development of the methodologies (WP3), the selection of “hot topics” and the analyses (WP 4-5-6-7) in order to ensure a systems approach is applied (i.e. Integration and comparability of results) and both the system requirements and the stakeholders’ needs are met.