Rune Elvik

Transportøkonomisk institutt, TØI · Safety and environment

The objective of this paper is to evaluate the effectiveness of the Safe System approach to road safety management, as implemented in Norway. The paper proposes simple operational definitions of key elements of the Safe System approach to road safety management. The relationship between these elements and changes over time in the number of killed o...

Vision Zero was adopted as the long-term ideal for transport safety in Norway in 2001. Starting in 2002, national road safety action plans covering a period of four years have been developed. This paper identifies innovative elements in these plans and explores the statistical relationship between innovation and the number of killed or seriously in...

There has been a large decline in the number of police reported injury accidents on public roads in Norway after 2007. The decline has been particularly large for accidents involving heavy goods vehicles. From 2007 to 2020, the number of heavy goods vehicles involved in injury accidents declined by 68%. The total number of injury accidents declined...

The main objective of the study is to evaluate direct and indirect traffic safety consequences of the requirements that Norway’s largest transit authority (Ruter) sets in the contracts with bus companies. To assess the representativity of Ruter’s requirements and its consequences, the data focuses both on Ruter and transit authorities from other ar...

During the period from 2007 to 2019, the number of drivers of heavy goods vehicles checked by the traffic police in Norway varied substantially. It declined during the first years of the period, then increased. This paper studies where there is an association between these variations and annual changes in the number of accidents involving heavy goo...

The present study investigated possible consequences for the number of killed and seriously injured (KSI) in traffic if trucking companies in Norway introduced the organisational safety management (OSM) measures in the stepwise approach called the “Safety Ladder” for road goods transport. The aim of the paper was to estimate the potential of OSM to...

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 these impacts as a starting point for quantitative impact assessment. The many interrelations between impacts increases the complexity of obtaining a com...

Sett fra en økonoms ståsted må transportmarkeder forstås med utgangspunkt i markedsteori og teorier for offentlige reguleringer. I kapitlene i denne boken er det benyttet en slik tilnærming for å diskutere ulike transportrelaterte problemstillinger. Temaene er mange, som for eksempel betydningen av skandinavisk transportforskning, prising av ferget...

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 these impacts as a starting point for quantitative impact assessment. The many interrelations between impacts increases the complexity of obtaining a com...

Introduction Costs related to road crashes represent an important societal burden. Additionally they constitute an essential input variable to assess the cost efficiency of road safety measures. While most attention is usually spent on costs related to fatal crashes, this paper focuses on costs related to serious injuries. Method A review of these...

Research problem This paper reviews and summarises studies of the risk of non-collision injuries to public transport passengers. Non-collision injuries include injuries when boarding or alighting and falls onboard as a result of e.g. sudden braking. It was possible to reconstruct exposure to risk for eleven studies, providing a total of twelve esti...

Introduction The economic value of safety represents an important guide to transport policy, and more studies on individuals’ valuation of road safety are called for. This paper presents a stated preference study of the value of preventing fatal and serious injuries involving bus passengers and car drivers in road accidents. Objectives Former valua...

Purpose – This chapter gives an overview of meta-analytic methods and illustrates the use of these methods for synthesising research findings. The advantages of performing a meta-analysis are described. Pitfalls in meta-analyses are also discussed. The chapter is intended to present the main elements of a meta-analysis and guide readers to literatu...

Studies of the relationship between access point density (number of access points, or driveways, per kilometre of road) and accident frequency or rate (number of accidents per unit of exposure) have consistently found that accident rate increases when access point density increases. This paper presents a formal synthesis of the findings of these st...

In several papers, Hauer (1988, 1989, 2000a, 2000b, 2016) has argued that the level of safety built into roads is unpremeditated, i.e. not the result of decisions based on knowledge of the safety impacts of design standards. Hauer has pointed out that the development of knowledge about the level of safety built into roads has been slow and remains...

This paper discusses how injuries sustained while cycling can be included as a component of health impact economic assessment of increased cycling. To include injuries as a component of a health impact assessment, their expected frequency of occurrence and impacts on health must well known. In this respect, incomplete reporting of cyclist injuries...

This paper presents a meta-analysis of the road safety effects of converting junctions to roundabouts. 44 studies containing a total of 154 estimates of effect were included. Based on a meta-regression analysis, converting junctions to roundabouts is associated with a reduction of fatal accidents of about 65% and a reduction of injury accidents of...

Safety inspectorates have been established for all modes of transport in Norway. This paper explores whether establishing a safety inspectorate is related to safety performance. Long-term trends in safety in aviation and rail were compared before and after safety inspectorates were established for these modes of transport. In aviation, there have b...

Barrier effects can impact cyclists’ travel time, level of comfort, and risk of accidents. When eliciting the valuation of these elements, simultaneous estimation is called for because the perceived level of comfort may depend on the accident risk. In this paper we present the results of a choice experiment in which cyclists traded off cycling time...

Recent research has proposed fitting responses from discrete choice experiments to asymmetric value functions consistent with prospect theory, taking into account respondents’ reference points in their valuation of choice attributes. Previous studies have mainly concentrated on travel time and cost attributes, while evidence regarding road safety a...

The Norwegian Public Roads Administration has asked for estimates of selected driver support systems with a potential to reduce the number of fatalities. The driver support systems considered were: Intelligent Speed Adaptation (ISA), maximum speed governor, Alcolock, seat-belt lock, sleep/fatigue warning system, programmable electronic ignition loc...

This paper presents a comparative analysis of the effects of economic policy instruments in promoting environmentally sustainable transport. Promoting environmentally sustainable transport is defined as follows: (1) Reducing the volume of motorised travel; (2) Transferring travel to modes generating less external effects, and (3) Modifying road use...

Path dependency, both institutional and technical, is a main challenge to the paradigm shift from dependence on private car to sustainable transport. An understanding of how policies at national and local levels can change the path dependency is of great importance for devising strategies and policies for the paradigm shift, and bypassing barriers...

Safety-in-numbers denotes a non-linear relationship between exposure (traffic volume) and the number of accidents, characterised by declining risk as traffic volume increases. There is safety-in-numbers when the number of accidents increases less than proportional to traffic volume, e.g. a doubling of traffic volume is associated with less than a d...

Studies of the relationship between characteristics of horizontal curves and accident rate have been reported in several countries. The characteristic most often studied is the radius of a horizontal curve. Functions describing the relationship between the radius of horizontal curves and accident rate have been developed in Australia, Canada, Denma...

Studies that have evaluated the effects on accidents of daytime running lights for cars have consistently found that cars using daytime running lights are involved in fewer multi-party accidents in daylight than cars not using daytime running lights. However, studies evaluating the effects of mandatory use of daytime running lights have not always...

Stated choice studies have been applied regularly to the valuation of time savings and other attributes of travelling as perceived by individuals. In such experiments, respondents often provide reference levels for the attributes and the hypothetical choices presented to them are pivoted around actual behaviour. However, most individuals are not ab...

Surveys finding that a large majority of drivers regard themselves as safer than the average driver have been ridiculed as showing that most drivers are overconfident about their safety and as showing something which is logically impossible, since in a normal distribution exactly half are below average and half above. This paper shows that this cri...

This paper reviews game-theoretic models that have been developed to explain road user behaviour in situations where road users interact with each other. The paper includes the following game-theoretic models: The models reviewed are different in many respects, but a common feature of the models is that they can explain how informal norms of behavi...

This paper reports an analysis of factors influencing safety in a sample of marked pedestrian crossings in the city of Oslo, Norway. The sample consists of 159 marked pedestrian crossings where a total of 316 accidents were recorded during a period of five years. The crossings were selected for inspection because of they were, for various reasons,...

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 enfor...

Conducting rigorous before-and-after studies is essential for improving knowledge regarding the effects of road safety measures. However, state-of-the-art approaches like the empirical Bayes or fully Bayesian techniques cannot always be applied, as the data required by these approaches may be missing or unreliable. The choice facing researchers in...

This paper introduces a simple statistical technique that can be used to assess the external validity of road safety evaluation studies. External validity refers to the possibility of generalising the results of research to other contexts than those in which it was made. There are several aspects of external validity. Two aspects that are often of...

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...

This paper presents an accident modification function for speed enforcement. The function describes the percentage effect of enforcement on the number of injury accidents as a function of the relative change in the amount of enforcement. Thirteen studies that have evaluated the effects of different levels of enforcement, each containing between fou...

This paper shows that the meta-analysis of bicycle helmet efficacy reported by Attewell, Glase, and McFadden (Accident Analysis and Prevention 2001, 345-352) was influenced by publication bias and time-trend bias that was not controlled for. As a result, the analysis reported inflated estimates of the effects of bicycle helmets. This paper presents...

This chapter provides the results of a limited cost–benefit analysis (CBA) on selected implementation scenarios. A main challenge for CBA of ITS-based safety measures is the limited quantifiable estimates of their effects on road fatalities and injuries. As a proxy to estimating such effects, an error-based approach is applied. That is, particular...

This review summarizes current knowledge regarding the effects of speed limit enforcement on public health. Speed limits are commonly used around the world to regulate the maximum speed at which motor vehicles can be operated on public roads. Speed limits are statutory, and violations of them are normally sanctioned by means of fixed penalties (tra...

This paper discusses the application of operational criteria of causality to multivariate statistical models developed to identify sources of systematic variation in accident counts, in particular the effects of variables representing safety treatments. Nine criteria of causality serving as the basis for the discussion have been developed. The crit...

This paper discusses how incentives for setting efficient priorities in road safety policy can be strengthened. Efficient priorities are characterised by the use of cost-effective road safety measures. Cost-effective road safety measures can be identified by means of cost-benefit analyses. Studies of the actual priorities in road safety policy, in...

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4(th) power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3(rd) power, and...

National road safety programmes have been developed in many motorised countries. Some of these programmes contain estimates of the safety benefits that were expected to be realised if the programmes were fully implemented. When these estimates are compared to actual outcomes, it is not uncommon to find large differences. This paper argues that diff...

Some road safety problems have persisted for a long time in nearly all motorised countries, suggesting that they are not easily solved. This paper documents the persistence over time of five such problems: the high risk of accidents involving young drivers; the high risk of injury run by unprotected road users; risks attributable to incompatibility...

This paper provides a restatement of the case for speed limits. The paper argues that driver speed choice cannot be granted any normative status (i.e. be regarded as optimal from a societal point of view) unless it is “objectively” rational, even if it can be reasonably interpreted as “subjectively” rational. A distinction between “subjective” and...

Statements about economic cost-benefit analysis were assessed in a sample of European road safety decision-makers. These statements related to both principles of cost-benefit analysis and implications for applying the method to road safety projects. A procedure of information reference testing was applied, under the assumption of identifying knowle...

This paper examines the stability of long-term trends in the number of traffic fatalities in eight highly motorised countries: Norway, Sweden, Denmark, Finland, The Netherlands, Great Britain, Australia and The United States. In all these countries, the number of traffic fatalities reached a peak around 1970-1972 and has since declined. The decline...

Previous research has found that the priority given to road safety measures is not based on the results of economic analyses, in particular cost–benefit analysis. This paper tries to identify some reasons for this fact. Knowledge utilisation theory is applied as a framework for identifying barriers. A typology of barriers to the use of economic eff...

Most road safety studies rely on summary measures of exposure. The term summary measure denotes any aggregate indicator of exposure that does not directly identify and count the number of opportunities for accidents to occur. This paper shows how elementary units of exposure can be developed on the basis of known aggregate measures, such as AADT. A...

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)]/[(Numbe...

Several studies show that the risks of injury to pedestrians and cyclists are highly non-linear. This means that the more pedestrians or cyclists there are, the lower is the risk faced by each pedestrian or cyclist. On the other hand, the more motor vehicles there are, the higher becomes the risk faced by each pedestrian or cyclist. The relationshi...

Road safety programmes consisting of a large number of road safety measures have been developed in many countries. To estimate the effects of such programmes on the number of accidents, models for estimating the combined effects of road safety measures are needed. This paper presents an exploratory analysis of such models. There is very little empi...

This paper discusses the relationship between efficiency and equity as objectives of road safety policy. The term efficiency refers to the efficient use of all road safety measures. Road safety measures are used efficiently if the priority given to them is based on the criterion that marginal social benefits should be at least equal to marginal soc...

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 al...

This paper presents the results of a survey of operational definitions of hazardous road locations in some European countries. The term operational definition refers to the criteria and methods used to identify hazardous road locations. Eight countries were included in the survey. The operational definitions of hazardous road locations used in thes...

This paper examines the predictive validity of empirical Bayes (EB) estimates of road safety. The predictive performance of EB-estimates was tested by applying five versions of EB-estimates of road safety: (1) A simple estimate derived from the empirical distribution of accidents in a population of sites, by which the number of accidents predicted...

The Norwegian Public Roads Administration has developed a comprehensive system of road safety management by objectives. A broad set of objectives regarding road user behaviour, vehicle safety standards and the safety of roads has been formulated as part of the National Transport Plan for the term 2010--2019. These objectives have been derived from...

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 identi...

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 complet...

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. T...

An extensive programme of periodic motor vehicle inspection was introduced in Norway after 1995, when the treaty between Norway and the European Union (EU) granting Norway (not a member of the EU) access to the EU inner market took effect (The EEA treaty). This paper evaluates the effects on accidents of periodic inspections of cars. Trucks and bus...

This paper discusses if it is appropriate to include the benefits that offenders get by violating the law in cost-benefit analyses of police enforcement, in the form of a loss of benefits from violations. The discussion is cast in the context of traffic law violations, a very common type of crime, which is usually not very strongly condemned from a...

This paper suggests that the influence of a number of important risk factors on road accidents can be described in terms of a few highly general statistical regularities that determine the shape of the relationship between the risk factors and accident occurrence. The statistical regularities are referred to as "laws of accident causation". The fol...

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...

This paper proposes a new approach to the analysis of accidents at hazardous road locations, one that is designed to make these analyses more effective in discriminating between true and false positives, that is, sites whose true expected number of accidents is high and sites where a high recorded number of accidents is predominantly the result of...

This paper discusses how the long-term frequency of major transportation accidents can be estimated for a small country such as Norway, for which the observed frequency may not be a good estimate for long-term frequency. A major transportation accident is defined as an accident in which there are at least five fatalities. Estimates of the long-term...

This paper probes the extent to which the public accurately perceives differences in transport risks. The paper is based on a survey of a random sample of the Norwegian population, conducted in September 2003. In the survey, respondents were asked: "How safe do you think it is to travel by means of (bus, train, etc.)?" Answers were given as: very s...

The features of a new car developed by Toyota engineers were presented at the Fourth Annual 'Year in Ideas'. The new has the ability to approximate the feelings of the driver by drawing on data stored in an on-board computer. The car has connections to the growing body of research on road, defensive driving, and other traffic safety consideration s...

This paper presents a systematic review of studies that have evaluated the effects on road safety of porous asphalt. Porous asphalt is widely used on motorways in Europe, mainly in order to reduce traffic noise and increase road capacity. A meta-analysis was made of six studies, containing a total of eighteen estimates of the effect of porous aspha...

This paper is an introductory guide to systematic reviews and metaanalysis. Meta-analysis is defined, and important textbooks are introduced. The types of research problems that lend themselves to meta-analysis, how to prepare for a meta-analysis, the main stages of the analysis itself, and how to present a meta-analysis are all discussed. Some bri...

This paper presents a study evaluating the power model of the relationship between speed and road safety. The power model states that a given relative change in the mean speed of traffic is associated with a relative change in the number of accidents or accident victims by means of a power function. An extensive review of relevant literature has be...

Every meta-analysis involves a number of choices made by the analyst. These choices may refer to, for example, estimator of effect, model for analysis (fixed effects or random effects), or the treatment of varying study quality. The choices made can affect the results of the analysis. Every meta-analysis should therefore include a sensitivity analy...

This paper proposes a conceptual framework that can be used to assess to what extent the findings of road safety evaluation research make sense from a theoretical point of view. The effects of road safety measures are modelled as passing through two causal chains. One of these, termed the engineering effect, refers to the intended effects of a road...

This paper presents an evaluation of the effects on road safety of new urban arterial roads in Oslo, Norway, and a synthesis of evidence from similar studies that have evaluated the safety effects of new urban arterial roads in other cities. A before-and-after study was made of four urban arterial road projects in Oslo. The study controlled for gen...

The selection for road safety treatment for national roads in Norway is examined. The main question asked is, To what extent are the sites selected for road safety treatment biased in favor of sites that have recorded an abnormally high number of accidents during the period before treatment? To answer this question, the observed accident rates at t...

This paper discusses how the validity of road safety evaluation studies can be assessed by analysing causal chains. A causal chain denotes the path through which a road safety measure influences the number of accidents. Two cases are examined. One involves chemical de-icing of roads (salting). The intended causal chain of this measure is: spread of...

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 fe...

A meta-analysis of studies reported outside the United States was performed to evaluate the effects on road safety of converting intersections to roundabouts. Twenty-eight studies that provided 113 estimates of effect were evaluated. State-of-the-art techniques of meta-analysis were applied to synthesize evidence from these evaluation studies. A me...

This paper presents a study of the effects on accidents of technical inspections of heavy vehicles (trucks and buses) in Norway. Multiple regression analysis is applied in order to estimate the effects of technical inspections, controlling for annual trend in accident rate, the number of new drivers and annual economic growth. It is found that abol...

This paper discusses the importance of confounding in observational before-and-after studies of road safety measures. The importance of the approach taken to controlling for confounding factors is shown by means of examples. It is shown that the size of the effect on accidents attributed to a road safety measure can be profoundly affected by which...

This paper presents a meta-analysis of 33 studies that have evaluated the effects on road safety of area-wide urban traffic calming schemes. Area-wide urban traffic calming schemes are typically implemented in residential areas in towns in order to reduce the environmental and safety problems caused by road traffic. A hierarchical road system is es...

This paper discusses the applicability of cost-benefit analysis as an aid to policy making for road safety measures. A framework for assessing the applicability of cost-benefit analysis is developed. Five main types of criticism of cost-benefit analysis are identified: 1. rejecting the basic principles of cost-benefit analysis as not applicable to...

This paper presents estimates of how much road accidents cost the national economy, stated as a percentage of the gross national product (GNP). Official estimates of road accident costs from 1990 or later were compiled from easily accessible sources for twelve countries. Estimates of the gross national product were taken from OECD publications. On...

This paper discusses the current state-of-the-art with respect to impact assessment and cost-benefit analysis of measures designed to improve safety or mobility for pedestrians and cyclists. The study concludes that a number of impacts that are likely to regarded as important for pedestrians and cyclists are not included in current impact assessmen...

The Swedish National Road Administration has launched a long term vision of a road transport system in which nobody is killed or sustains an injury resulting in permanent impairment (Vision Zero). This paper examines some possible implications of Vision Zero for traffic fatalities. The main points of the paper can be summarised as follows: An objec...

Studies that have evaluated the effects on accidents of studded tires are reviewed. There are two types of evaluation studies with respect to the safety effects of studded tires: (1) Studies of the effect on automobile accident rates of using studded tires; and (2) studies of the effect on accidents of banning the use of studded tires. The results...

A meta-analysis of studies of road accident reporting in official accident statistics made in 13 countries is described here. A rigorous comparison of reporting levels between countries is difficult because of differences in the definitions of reportable accidents, reporting levels, and data sources used to assess reporting levels. Based on 49 stud...

The validity of weighted mean results estimated in meta-analysis has been criticized. This paper presents a set of simple statistical and graphical techniques that can be used in meta-analysis to evaluate common points of criticism. The graphical techniques are based on funnel graph diagrams. Problems and techniques for dealing with them that are d...

The peer review system of scientific journals is commonly assumed to prevent seriously flawed research from getting published. This paper compares the quality of 44 road safety evaluation studies published in peer reviewed journals to the quality of 79 evaluation studies dealing with the same safety measures, but not published in peer reviewed jour...

Numerous evaluation studies have reported large accident reductions when road accident blackspots are treated. A critical examination of these studies reveals that many of them do not account for the effects of well known confounding factors, like the regression-to-the-mean effect that is likely to occur at road accident blackspots. This paper show...

A meta-analysis of 17 studies that have evaluated the effects on traffic safety of using daytime running lights (DRL) on cars is presented. A distinction is made between studies that have evaluated the effects of DRL on the accident rates of each car using it and studies that have evaluated changes in the total number of accidents in a country foll...

Studies evaluating the effects of traffic safety measures are often done for the purpose of predicting the effects of future applications of the measures. The predictive value of evaluation studies is unknown. Some general arguments for and against attributing a general predictive value to the results of evaluation studies are discussed. Predictabi...

Evidence from 32 studies that have evaluated the safety effects of median barriers, guardrails along the edge of the road, and crash cushions (impact attenuators) is summarized by means of a meta-analysis. Two hundred and thirty-two (232) estimates of safety effects are included in the meta-analysis. The presence of publication bias is tested by me...

This paper describes an assessment of the validity of using health state indexes as a means of describing the consequences of traffic injury for public health. Three issues are discussed: (1) Can questionnaire data be used as input for estimating health state values by means of health state indexes? (2) Can the validity of describing the consequenc...

Official economic valuations (costs) of a traffic accident fatality in 20 motorized countries are described. The economic valuation per fatality varies from 0.87 million Norwegian kroner to 17.80 million kroner. The mean value is 5.69 million kroner. An attempt is made to explain the differences in official cost estimates. The valuation method used...