Vlakveld W.P.,SWOV Institute for Road Safety Research
Transportation Research Part F: Traffic Psychology and Behaviour | Year: 2014
In PC-based hazard perception tests scores are traditionally based on how quickly participants respond to developing hazards in video clips. A disadvantage of this method is that latent hazards which do not develop into acute threats cannot be included in the test. The present study compared two tasks using the same stimuli but with different response methods. The stimuli consisted of thirteen animated video clips in which latent hazards did not materialize. Latent hazards could either be a visible other road user who due to the circumstances could start to act dangerously, or a hidden other road users who could be on collision course. The first-mentioned were the overt latent hazards and the latter were the covert latent hazards. In Task 1, participants had to indicate what the high priority latent hazard was after they had watched a clip. In Task 2, participants could indicate latent hazards while they were watching a clip and decide afterwards which of the indicated latent hazards had the highest priority. In both tasks the scores were based on how many high priority latent hazards were detected and were not based not on response times. Professional drivers (driver trainers and driving examiners) and learner drivers were randomly assigned to a group that performed Task 1 and a group that performed Task 2. Professionals scored significantly better on both tasks than learner drivers. Although in both tasks professionals scored significantly higher, Task 1 seems to be a more promising alternative for the traditional hazard perception test than Task 2 because professional drivers scored significantly higher on overt latent hazards than learner drivers in Task 1 but not in Task 2 and experience with computer games influenced the scores in Task 2 but not in Task 1. A weakness of Task 1 was its rather low internal consistency (α =.69). © 2013 Elsevier Ltd. All rights reserved.
Dijkstra A.,SWOV Institute for Road Safety Research
Transportation Research Part C: Emerging Technologies | Year: 2013
In the Netherlands, the concept 'Sustainable Safety' is the leading vision in road safety policy and research. The main goal of a sustainably safe road transport system is to reduce the annual number of road crash casualties to a fraction of the current levels. An important requirement that follows from this vision is that the quickest route and the safest route should coincide. This paper focuses on the design of a method which enables the planner to establish the safety effects of existing route choice, and also those of changes in route choice. The traffic safety assessment is carried out by quantifying the safety level of a route on the basis of those characteristics of the route that are assumed to be related to safety. This paper examines the quantitative relationship between the assessment of the route's safety level and the conflicts (at junctions) involving vehicles travelling along that route. These conflicts are detected in a micro-simulation model. Different routes in a regional network which were travelled by the modeled vehicles were used for the analysis.This method of quantifying the safety level of routes will make it possible to evaluate road network structures from a safety perspective. It is expected that by optimising the design of the network and by influencing route choice a (more) sustainably safe traffic system can be achieved. © 2012 Elsevier Ltd.
Wegman F.,SWOV Institute for Road Safety Research |
Oppe S.,SWOV Institute for Road Safety Research
Safety Science | Year: 2010
In order to obtain political interest in road safety problems and to learn from other countries' 'good practices', it is often helpful to compare one's own safety situation with that of other countries. In a number of projects tools have been developed for such comparisons. These tools range from simple ratings of countries on their safety outcomes, such as the annual number of fatalities per capita or per kilometre driven by (motor)vehicles to more comprehensive comparisons.These comparisons not only show differences in safety between countries, but to a certain extent also explain such differences in terms of their safety background and measures taken. Finally, tools have been defined to support road safety policy makers in developing possible safety measures or actions. Procedures for such complex safety comparisons have been developed and tested in several so-called SUNflower studies.This promising approach can be further developed into standard procedures for safety comparisons between all countries in the European Union, and other countries worldwide. This paper wishes to outline the development of such standards for the benchmarking of road safety and safety trends as well as procedures for quantifying safety performances of countries.Starting point of this conceptual framework is the so-called SUNflower-pyramid in which three types of indicators are distinguished. The first one of these, the road safety performance indicator, is called an outcome indicator and is based on the number of killed and injured road users. The second indicator type indicates the quality of the implementation of road safety policies: the implementation performance indicators. The third type of indicator indicates the quality of response in policy documents to improve road safety (policy performance indicator). The three types of indicators are embedded in a policy context: the structure and culture of a country, which are considered as background variables.This paper sets out to describe the framework for the development of a comprehensive set of indicators to benchmark road safety performances of countries or of sub-national jurisdictions. The paper also discusses the advantages and disadvantages of combining such indicators and if combined, how to aggregate how different indicators in one composite performance index. It is argued to group countries in different classes with more or less comparable countries. Different procedures are used for this grouping. The results are promising and it is recommended to work with classes of countries. © 2010 Elsevier Ltd.
van Nes N.,SWOV Institute for Road Safety Research |
Brandenburg S.,TU Berlin |
Twisk D.,SWOV Institute for Road Safety Research
Accident Analysis and Prevention | Year: 2010
Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12 road sections in a driving simulator. The speed limit system (static-dynamic), the sophistication of the dynamic speed limit system (basic roadside, advanced roadside, and advanced in-car) and the situational condition (dangerous-non-dangerous) were varied. The homogeneity of driving speed, the rated credibility of the posted speed limit and the acceptance of the different dynamic speed limit systems were assessed. The results show that the homogeneity of individual speeds, defined as the variation in driving speed for an individual subject along a particular road section, was higher with the dynamic speed limit system than with the static speed limit system. The more sophisticated dynamic speed limit system tested within this study led to higher homogeneity than the less sophisticated systems. The acceptance of the dynamic speed limit systems used in this study was positive, they were perceived as quite useful and rather satisfactory. © 2009 Elsevier Ltd. All rights reserved.
Weijermars W.,SWOV Institute for Road Safety Research |
Wegman F.,SWOV Institute for Road Safety Research
Transportation Research Record | Year: 2011
In the 1990s, the Institute for Road Safety Research (SWOV) in the Netherlands introduced the vision of sustainable safety. In a sustainably safe traffic system, crashes are prevented as much as possible, and when prevention is not possible, the probability of severe injury is reduced to almost zero. In 1998, implementation of the vision commenced with the start-up program. Ten years after the start-up program, there was an investigation of how implementation of the measures that emanated from or were in line with the vision of sustainable safety had progressed and what effects these measures have had on safety. The assessment indicated that a substantial number of traffic safety measures were implemented from 1998 through 2007. Many actions taken within the framework of the start-up program were aimed at improving infrastructure safety; the most important actions were categorization of the road network and traffic calming measures such as the construction of 30-and 60-km/h zones. In addition, traffic enforcement increased as a result of the establishment of dedicated regional traffic enforcement teams. The crashworthiness of vehicles also improved. These measures had a positive effect on traffic safety. Each individual measure prevented casualties. Moreover, the fatality rate decreased from 7.3 fatalities per billion kilometers traveled in 1998 to 4.7 per billion in 2007. It is estimated that together the measures prevented 300 to 400 fatalities in 2007 (32% to 34% fewer than expected) and 1,600 to 1,700 fatalities from 1998 through 2007. Finally, a benefit-cost analysis indicates that the measures were also cost beneficial (benefit-cost ratio 3.6:1).