Value of Research About the Safety Effect of Actions (original) (raw)

Value of Research on Safety Effects of Actions

Transportation Research Record: Journal of the Transportation Research Board, 2012

Money ought to be spent on research that promises most value for the buck; but how is one to estimate the value?. This paper suggests a logical and quantitative approach to estimating the valueforaclassofproposedroadsafetyresearchprojectsresearchtoestimatethesafetyeffectofvariousactions.Theaimofsuchresearchistoimprovingourabilitytopredict.Themoreaccuratelyonecanpredictthesafetyeffectofsomeactionthefewerincorrectdecisionswillbemade.Withmoredecisionscorrectinvestmentismorecost−effective.Thisiswhatgivessuchresearchitsvalue.Thetaskofassigningvalue for a class of proposed road safety research projectsresearch to estimate the safety effect of various actions. The aim of such research is to improving our ability to predict. The more accurately one can predict the safety effect of some action the fewer incorrect decisions will be made. With more decisions correct investment is more cost-effective. This is what gives such research its value. The task of assigning valueforaclassofproposedroadsafetyresearchprojectsresearchtoestimatethesafetyeffectofvariousactions.Theaimofsuchresearchistoimprovingourabilitytopredict.Themoreaccuratelyonecanpredictthesafetyeffectofsomeactionthefewerincorrectdecisionswillbemade.Withmoredecisionscorrectinvestmentismorecost−effective.Thisiswhatgivessuchresearchitsvalue.Thetaskofassigning-value to a proposed research is doable. The logic and the computations are described. The estimated $-value, when coupled with the cost of research, can used to prioritize proposed research projects.

A decision analytic approach to the design of experiment in road safety

We start by erecting a framework of thought on which to base the computation of the '"expected value of a research study". On this basis, it is possible to demonstrate that the juxtaposition of study value and study cost leads to research programme and study size decisions without the need to resort to arbitrary convention. As study size grows, its value approaches an upper bound. Exploration of this upper bound -the value of perfect information -is particularly instructive. In conclusion, we apply the methodology to a simplified "case study" which revolves around the research into the effect of mandating in Canada the use of headlights during the day.

Evaluating the benefits of road safety research: the case of Sweden

This paper summarises a study designed to answer the following question: what are the benefits to 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 a...

Computing what the public wants: Some issues in road safety cost–benefit analysis

Accident Analysis & Prevention, 2011

In road safety, as in other fields, cost-benefit analysis (CBA) is used to justify the investment of public money and to establish priority between projects. It amounts to a computation by which 'few'-the CB analysts-aim to determine what the 'many'-those on behalf of which the choice is to be made-would choose. The question is whether there are grounds to believe that the tool fits the aim. I argue that the CBA tool is deficient. First, because estimates of the value of statistical life and injury on which the CBA computation rests are all over the place, inconsistent with the value of time estimates, and government guidance on the matter appears to be arbitrary. Second, because the premises of New Welfare Economics on which the CBA is founded apply only in circumstances which, in road safety, are rare. Third, because the CBA requires the computation of present values which must be questioned when the discounting is of future lives and of time. Because time savings are valued too highly when compared to life and because discounting tends to unjustifiably diminish the value of lives saved in the future, the CBA tends to bias decisions against investment in road safety.

ESTIMATING BENEFITS FROM SPECIFIC HIGHWAY SAFETY IMPROVEMENTS

In the past thirty years, highway fatality rates have declined steadily because, most notably, of dramatic changes in motor vehicle design, passage of laws making seat belt use mandatory and driving while intoxicated a criminal offense, and educating the public through focused advertising campaigns. However, the practice of highway design has changed little.

Cost-Benefit Analysis of Road Safety Measures

2013

Road accidents represent one of the most serious problems faced by the Ministries of Public Health in the World. In Italy for example, in the year 2007 there were almost 330, 000 injuries and 5, 131 fatalities; 230, 871 crashes in all which resulted in an estimated € 30.4 billion financial loss, corresponding to 2% of GDP. In 1999 the National Road Safety Plan (NRSP), among other things, funded the requalification of several unsafe road infrastructures at higher risk of accidents. Unlike other infrastructure investment plans, NRSP usually requires: i) specific safety analysis of crash history to identify the critical road; ii) proactive action, e.g. RSAs and RSARs; iii) before-after accident study; iv) ex-post monitoring of road user behaviors, etc. The paper presents some unsafe roads in urban and suburban areas which were renovated through NRSP strategies and whose projects were submitted to Road Safety Audit procedure for black spot treatment. It examines the effect of physical t...

Evaluation of Safety Impact of Highway Projects

1993

An empirical Bayesian approach to evaluate the safety impact of highway projects at a group of sites level was developed. Rural traffic accident data from the state of Indiana were used. The Bayesian methodology was illustrated using examples of wedge and level and resurfacing projects. The results indicated that wedge and level and resurfacing activities did not have a significant effect on the level of the expected number of accidents or accident rates at 95% probability level on Indiana's two-lane rural roads having traffic volumes less than 4,000 vehicles per day.

Explicit Consideration of Safety in the Transportation Planning Process

2017

This report develops a methodology for the Explicit Consideration of Safety in the Transportation Planning Process by focusing on science-based and data-driven project selection, which considers susceptibility to cost-effective correction rather than simply observed frequency and severity of crashes. Only a very small percentage of projects (4 percent or less in Colorado) are exclusively safety motivated and funded. Most projects are aimed at some combination of mobility, pavement preservation, maintenance, improved air quality, operations as well as safety. Safety consideration is present explicitly or implicitly in most transportation infrastructure projects and the challenge is to bring safety to a common denominator with other goals of the project. The actual planning process is influenced not only by scientifically estimated objective benefits and costs, but also by the availability of funding, political climate, and other intangible factors. Nevertheless, with all other things being equal, the proposed methodology provides a quantitative framework for decision makers in selecting and ranking transportation projects.

Potential for Safety Improvement of Existing Roads

Safety reviews of existing roads aim to identify any features which may lead to future crashes, so that remedial treatments may be implemented before crashes happen. Safety reviews are complementary and not alternative to accident investigation studies. Accident investigation is a "reactive programme", it examines past accidents and aims to remove or change the features that contributed to those past crashes. Safety review is a "proactive programme", aimed at reducing road accidents before they occur. Accident investigation tend to concentrate on single locations, whereas safety reviews are more akin to mass action studies. Safety reviews may be high cost-effective, but the subjective nature of the process may give rise to inconsistencies which limit their effectiveness. To address this issue, a technique to support road safety reviews in order to quantify the safety gains that could be achieved by addressing the problems identified in the review process is presented. The approach is based on known accident relationships, and a systematic process has been described to determine which road features should be investigated and how each feature should be evaluated during the review. As a result of the process, a potential for safety improvement index (PFI) is calculated. PFI represents a measure of the accident increase due the identified safety items. That is, PFI is a measure of the safety gains which can be obtained by eliminating the safety issues. The validity of the PFI has been evaluated by comparing the results of the PFI index, which has been assessed in 400 kms of rural two lane highways, with expected collision frequency. Collision frequency has been determined by applying a collision prediction model, calibrated in the study network, and has been refined by applying the Empirical Bayes technique. Correlation between EB safety estimates and PFI values is highly significant, with 93% of the variation in the estimated number of accidents explained by the PFI value. The level of agreement between the results of the EB estimates and the PFI has been evaluated also by the Spearman's rank-correlation coefficient. Sites were ranked according to both the EB estimate and PFI, with the results of the Spearman correlation indicating agreement at a 99.9% significance level. Due to the validation and quantifiable nature of the PFI, the procedure can be used to support road safety reviews, accident investigation, and decision-making. High risk segments, where safety measures that can reduce accident frequency and/or severity do exist, and specific safety issues, which contribute to unsafety, can be identified. The procedure can be helpful also to support the safety reviews carried out on low volume roads, where often accurate accident data do not exist.