First steps towards a holistic impact assessment methodology for connected and automated vehicles.

Connected and automated vehicles have become more common in recent years, increasing the need to assess their societal level impacts. In this paper a methodology is presented to explore and define relevant impact areas as a starting point for quantitative impact assessment. The many interrelations between impact areas increases the complexity of obtaining a complete overview. Therefore, a structured approach is used, which shows many similarities with the modelling of causal-loop-diagrams. Feedback loops between impact areas are taken into account at an early stage and methods of literature research, project team feedback, interrelation assessment and grouping are used to produce a holistic overview of impacts. The methodology was developed and applied in the European H2020 project LEVITATE. The impact taxonomy and interrelations between impact areas resulting from this project are presented and further steps needed to perform a quantitative evaluation of the impacts are discussed.

Can the use of road safety measures on national roads in Norway be interpreted as an informal application of the ALARP principle?

The ALARP principle, stating that risks should be reduced to a level "As Low As Reasonably Practicable", is widely known and discussed in risk management. The principle is flexible, as the interpretation of the key concepts of reasonable and practicable can be adapted to different contexts. This paper discusses whether the use of road safety measures on national roads in Norway can be interpreted as an informal application of the ALARP-principle. According to official guidelines, priority setting for major road investments should be based on cost-benefit analysis. Most road safety measures are low-cost projects that have traditionally not been subject to cost-benefit analysis. A use of these measures regarded as reasonable in the ALARP sense may include considerations of cost, efficiency and fair distribution. Data on 328 road safety measures implemented around 2000 is used to evaluate factors influencing their use. It is argued that the use of these measures is consistent with an informal application of the ALARP-principle.

A systematic cost-benefit analysis of 29 road safety measures.

Economic evaluations of road safety measures are only rarely published in the scholarly literature. We collected and (re-)analyzed evidence in order to conduct cost-benefit analyses (CBAs) for 29 road safety measures. The information on crash costs was based on data from a survey in European countries. We applied a systematic procedure including corrections for inflation and Purchasing Power Parity in order to express all the monetary information in the same units (EUR, 2015). Cost-benefit analyses were done for measures with favorable estimated effects on road safety and for which relevant information on costs could be found. Results were assessed in terms of benefit-to-cost ratios and net present value. In order to account for some uncertainties, we carried out sensitivity analyses based on varying assumptions for costs of measures and measure effectiveness. Moreover we defined some combinations used as best case and worst case scenarios. In the best estimate scenario, 25 measures turn out to be cost-effective. 4 measures (road lighting, automatic barriers installation, area wide traffic calming and mandatory eyesight tests) are not cost-effective according to this scenario. In total, 14 measures remain cost-effective throughout all scenarios, whereas 10 other measures switch from cost-effective in the best case scenario to not cost-effective in the worst case scenario. For three measures insufficient information is available to calculate all scenarios. Two measures (automatic barriers installation and area wide traffic calming) even in the best case do not become cost-effective. Inherent uncertainties tend to be present in the underlying data on costs of measures, effects and target groups. Results of CBAs are not necessarily generally valid or directly transferable to other settings.

How to trade safety against cost, time and other impacts of road safety measures.

Public policy, including road safety policy, involves balancing competing values against each other. Several techniques of policy analysis, most prominently cost-benefit analysis, have been developed to help policy makers prioritize between different values. Valuation studies have not produced credible monetary values of life and limb. Cost-benefit analysis therefore cannot tell when the "right" balance has been struck between road safety and other objectives of transport policy. All formal tools of policy analysis are likely to reflect analyst values to a major extent, not the values of policy makers only. It is argued that policy choices and tradeoffs can be informed simply by providing factual information about impacts and not attempting to impose any value judgements. A widely applicable metric is to state impacts as changes in human longevity and health state.

The European road safety decision support system on risks and measures.

The European Road Safety Decision Support System (roadsafety-dss.eu) is an innovative system providing the available evidence on a broad range of road risks and possible countermeasures. This paper describes the scientific basis of the DSS. The structure underlying the DSS consists of (1) a taxonomy identifying risk factors and measures and linking them to each other, (2) a repository of studies, and (3) synopses summarizing the effects estimated in the literature for each risk factor and measure, and (4) an economic efficiency evaluation instrument (E3-calculator). The DSS is implemented in a modern web-based tool with a highly ergonomic interface, allowing users to get a quick overview or go deeper into the results of single studies according to their own needs.

How did the economic recession (2008-2010) influence traffic fatalities in OECD-countries?

This paper presents analyses of how the economic recession that started in 2008 has influenced the number of traffic fatalities in OECD countries. Previous studies of the relationship between economic recessions and changes in the number of traffic fatalities are reviewed. Based on these studies, a causal diagram of the relationship between changes of the business cycle and changes in the number of traffic fatalities is proposed. This causal model is tested empirically by means of multivariate analyses and analyses of accident statistics for Great Britain and Sweden. Economic recession, as indicated both by slower growth of, or decline of gross national product, and by increased unemployment is associated with an accelerated decline in the number of traffic fatalities, i.e. a larger decline than the long-term trend that is normal in OECD countries. The principal mechanisms bringing this about are a disproportionate reduction of driving among high-risk drivers, in particular young drivers and a reduction of fatality rate per kilometre of travel, probably attributable to changes in road user behaviour that are only partly observable. The total number of vehicle kilometres of travel did not change very much as a result of the recession. The paper is based on an ITF-report that presents the analyses in greater detail.

Association between increase in fixed penalties and road safety outcomes: A meta-analysis.

Studies that have evaluated the association between increases in traffic fine amounts (fixed penalties) and changes in compliance with road traffic law or the number of accidents are synthesised by means of meta-analysis. The studies were few and different in many respects. Nine studies were included in the meta-analysis of changes in compliance. Four studies were included in the meta-analysis of changes in accidents. Increasing traffic fines was found to be associated with small changes in the rate of violations. The changes were non-linear. For increases up to about 100%, violations were reduced. For larger increases, no reduction in violations was found. A small reduction in fatal accidents was associated with increased fixed penalties, varying between studies from less than 1-12%. The main pattern of changes in violations was similar in the fixed-effects and random-effects models of meta-analysis, meta-regression and when simple (non-weighted) mean values were computed. The main findings are thus robust, although most of the primary studies did not control very well for potentially confounding factors. Summary estimates of changes in violations or accidents should be treated as provisional and do not necessarily reflect causal relationships.

Assessing the efficiency of priorities for traffic law enforcement in Norway.

This paper assesses the efficiency of priorities for traffic law enforcement in Norway. Priorities are regarded as efficient if: (1) enforcement ensures a sufficient level of deterrence to keep down the rate of violations; (2) selection of target violations for enforcement is based on the risk attributable to them; and (3) an optimal level of enforcement is selected, i.e. the marginal benefits of enforcement in terms of preventing accidents equal the marginal costs of enforcement. The efficiency of current traffic law enforcement in Norway is assessed in terms of these criteria. It is found that the risk of apprehension varies considerably between different traffic violations. These variations do not reflect the risk attributable to the violations, i.e. it is not the case that the risk of apprehension is higher for violations that make a large contribution to fatalities and injuries than for violations that make a smaller contribution. In principle, shifting priorities so as to increase the risk of apprehension for some violations and reduce it for other violations could make police enforcement slightly more efficient. The main finding, however, is that the current level of enforcement is too low. Cost-benefit analyses show that substantially increasing the amount of police enforcement is cost-effective.

A framework for a critical assessment of the quality of epidemiological studies of driver health and accident risk.

A large number of studies have tried to assess how various aspects of driver health influence driver involvement in accidents. The objective of this paper is to provide a framework for a critical assessment of the quality these studies from a methodological point of view. Examples are given of how various sources of bias and confounding can produce study findings that are highly misleading. Ten potential sources of error and bias in epidemiological studies of the contribution of driver health impairments to road accidents are discussed: (1) Poor description of the medical conditions whose effects are studied (measurement error). (2) Inadequate control for the effects of exposure on accident rate. (3) Sampling endogeneity with respect to assessment for fitness to drive (outcome-based sampling; self-selection bias). (4) Combined exposure to several risk factors. (5) Poor control for potentially confounding factors. (6) Failure to specify potentially moderating factors (interaction effects). (7) Failure to consider a severity gradient with respect to the effect of health impairments. (8) Failure to specify the compliance of drivers with medical treatments or treatment effectiveness. (9) No data on the population prevalence of various health conditions. (10) The use of multiple study approaches and methods making the comparison and synthesis of findings difficult. Examples are given of how all these items may influence the findings of a single study or make synthesising findings from multiple studies difficult. A checklist for assessing study quality is provided.

A new method for assessing the risk of accident associated with darkness.

This paper presents a new method for assessing the risk of accidents associated with darkness. The method estimates the risk of accident associated with darkness in terms of an odds ratio, which is defined as follows: [(number of accidents in darkness in a given hour of the day)/(number of accidents in daylight in the same hour of the day)]/[(Number of accidents in a given comparison hour when the case hour is dark)/(Number of accidents in a given comparison hour when the case hour is in daylight)]. This estimate of the risk of accident associated with darkness does not require data on exposure, but relies on the count of accidents in the same pair of hours throughout the year. One of the hours is dark part of the year, but has daylight the rest of the year. The comparison hour, which has daylight the whole year, is used to control for seasonal variations. The aim of relying on the same pair of hours throughout the year is to minimise the influence of potentially confounding factors. Estimates of the risk of injury accidents associated with darkness are developed on the basis of accident data for Norway, Sweden and the Netherlands. It is found that the risk of an injury accident increases by nearly 30% in darkness in urban areas, by nearly 50% in rural areas, and by about 40% for urban and rural areas combined (adjusted estimate).

Costs and benefits to Sweden of Swedish road safety research.

This paper summarises a study designed to answer the following question: what are the benefits to Swedish society of road safety research in Sweden funded by the Swedish Transport Research Council and the programme for vehicle safety research during the period 1971-2004? The paper starts by discussing whether research can answer this question at all and explains why a well-controlled study was not feasible. A case study approach was selected, and five major research projects were examined in detail for the purpose of trying to estimate their effects on road safety. Estimates of safety effects were developed for four of the projects, indicating that road safety measures that were at least to some extent based on the findings of the research projects have made major contributions to reducing the number of road accident fatalities in Sweden. The estimates are not analytically rigorous and should be treated as qualified guesses only. Causal inferences are not possible. Nevertheless, if taken at face value, they show that the benefits to society of road safety research are large and outweigh by a wide margin the costs of the research, and of the road safety measures developed as a result of research. Thus, even if the estimated safety benefits exaggerate the true effects, the benefits of applied road safety research are likely to be greater than the costs of conducting this research and implementing road safety measures developed by research.

Dimensions of road safety problems and their measurement.

This paper identifies nine characteristics of road safety problems that are all in principle amenable to numerical measurement. The nine characteristics identified are: 1. Magnitude 2. Severity 3. Externality 4. Inequity 5. Complexity 6. Spatial dispersion 7. Temporal stability 8. Perceived urgency 9. Amenability to treatment. The purpose of identifying these dimensions and of trying to measure them is to provide a basis for selecting problems for treatment by means of safety programmes. Selecting problems for treatment usually cannot be done on the basis of a single dimension, as it is the mix of characteristics that determine the prospects for successfully treating a problem. It is proposed that amenability to treatment is a function of complexity, perceived urgency and the availability of cost-effective treatments. Speed and speeding is used as an example of a road safety problem to illustrate how the various dimensions can be measured.

The deterrent effect of increasing fixed penalties for traffic offences: the Norwegian experience.

PROBLEM: Many motorized countries use fixed penalties to deter the most common traffic violations. Fixed penalties are usually given at the spot by a police officer. If the offender accepts the fixed penalty, no court hearing or trial is held. During the years 1995-2004, the rates for fixed penalties for traffic offences in Norway increased substantially. This paper evaluates the effects on compliance of these increases. METHOD: Regression analysis was performed to determine the effects of increases in fixed penalties. RESULTS: For speeding in general, no effect of increasing fixed penalties can be found. For speeding close to speed camera sites, there is a weak tendency for the violation rate to go down. This tendency is not statistically significant at conventional levels. For seat belt wearing, wearing rates are found to increase as fixed penalties have increased. In recent years, however, enforcement of the seat belt law has stepped up, making it impossible to separate the effect of enforcement from that of fixed penalties. IMPACT ON INDUSTRY: It has been suggested that the police may adapt to stricter penalties by reducing enforcement or by adopting larger tolerance margins for violations. Available evidence does not support this hypothesis.

Total costs of bicycle injuries in Norway: correcting injury figures and indicating data needs.

Bicycle injuries and fatalities are reported by the police to Statistics Norway. Fatality records from the police are then corrected with Vital Statistics records. However, there is no complete hospital recording that could provide more correct data for bicycle injuries. Bicycle injuries are underreported in official data. There is a nearly complete omission of single bicycle accidents. This disguises societal accident costs and curtails the identification of black spots and effective infrastructure improvements. This paper provides an estimate of total bicycle injuries in Norway and the total costs of these injuries. Application of case study hospital data from Norwegian towns enabled an estimation of the relationship between these data and the official data, including the distribution of injuries by severity. Costs were then assessed by applying official monetary values for given levels of injury severity. Total annual bicycle injury costs are huge, but these costs must be balanced against the benefits of bicycling, related to health and environment. Accident reporting and data should be enhanced to enable a reduction of bicycle injuries.

Economic deregulation and transport safety: a synthesis of evidence from evaluation studies.

This paper presents a synthesis of evidence from studies that have evaluated the impacts of economic deregulation on transport safety. Most of these studies refer to aviation or road transport. Very few studies deal with deregulation of rail transport. There are no studies of maritime transport, which has never been regulated the same way as other modes of transport. The review includes studies that have attempted to quantify the impacts of transport deregulation on transport safety. Each study contains one or more estimates of the effect on transport safety of deregulation. Summary estimates of effect have been derived from the individual estimates of effect by means of meta-analysis. Airline deregulation, which has only been evaluated in the United States, does not appear to influence the safety of air travel. Deregulation of road transport has been evaluated in several countries. The summary estimate of effect indicates that no statistically significant changes in road safety have occurred as a result of deregulation. Deregulation of rail transport has only been evaluated in Great Britain and the United States. The experience so far suggests that deregulation of railways is associated with improved rail safety. This association does, however, not necessarily imply a causal relationship.

How would setting policy priorities according to cost-benefit analyses affect the provision of road safety?

This paper analyses how setting priorities for road safety strictly according to cost-benefit analysis would affect the provision of road safety in Norway and Sweden. The paper is based on recent analyses of the efficiency of road safety policies in these two countries. The argument sometimes made by critics of cost-benefit analysis, that only a few road safety measures are cost-effective (have benefits greater than costs), is not supported. Cost-effective road safety policies could prevent between 50 and 60% of the current number of road accident fatalities in both Norway and Sweden, if pursued consistently during a period of 10 years (2002-2011). If current policies are continued, only about 10-15% of the current number of road accident fatalities are likely to be prevented during the next 10 years. A number of sources of inefficiency in road safety policy are identified. A source of inefficiency is anything that prevents policy priorities from being set according to cost-benefit analysis. These include: (a) lack of power, which means that national governments do not have the formal authority to introduce a certain road safety measure, in Europe, this applies to new vehicle safety standards, which are passed almost exclusively by the European Union; (b) the existence of social dilemmas, which means that measures that are cost-effective from a societal point of view are not so from the point of view of individual road users; (c) priority given to other policy objectives, in particular regional development. Scarcity of resources, which obtains when public budgets have to be increased to make room for all cost-effective measures, was not found to be a constraint. All cost-effective measures can be funded within current budgets, provided the use of inefficient measures ceases.

Cost-benefit analysis of ambulance and rescue helicopters in Norway: reflections on assigning a monetary value to saving a human life.

This paper reports the results of a cost-benefit analysis undertaken in 1996 for a public commission set up to plan the future operation of state-owned ambulance and rescue helicopters in Norway. The analysis indicates that the benefits of ambulance missions flown by helicopters exceeds the costs by a factor of almost six. To do this analysis it was necessary to assign a monetary value to human life. Traditionally this has not been done in medicine, and may be widely regarded as inconsistent with medical ethics. The results of the cost-benefit analysis serve as the starting point to a more general discussion surrounding the economic value of activities designed to reduce human mortality. It is concluded that human preferences for the provision of health care or other life-saving interventions are probably too complex to be adequately represented by means of a single monetary value expressing the benefits of life-saving. The task of developing an inclusive framework for a normative approach to priority setting in injury prevention is daunting, and may be insoluble. It is important to assess the extent to which current value-of-life estimates depend on study methods and social context.