This work estimates the total safety effects of speed limit changes on high-speed roadways using traffic detector data and Highway Safety Information System (HSIS) data from 1993 to 1996. In order to gauge the total effects, this study applies a sequential modeling approach in which average speed and speed variance models are first estimated, based on roadway design, use and speed limit information. Then, crash counts (of varying severity) are estimated, based on the speed estimates, design, and use variables. The four years of data come from 63,937 “homogeneous ” roadway segments along 7 interstates and 143 state highways in Washington State. A random-effects negative binomial model was selected among several alternative panel and non-panel models for count data. Results indicate that the average road segment in the data set can be expected to exhibit lower non-fatal crash rates up to a 55 mph speed limit. By contrast, fatality rates appear unresponsive to speed limit changes. Fatal and non-fatal rates fall for design reasons, including wider shoulders and more gradual curves, which appear to be key design variables. However, fatal and non-fatal rates move differently when traffic levels rise, with non-fatal rates remaining unchanged and fatal rates falling.

the Federal Highway Administration, and was conducted in the National Cooperative Highway Research Program (NCHRP), which is administered by the Transportation Research Board (TRB) of the National Academies. COPYRIGHT PERMISSION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FTA, or Transit Development Corporation endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-forprofit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. DISCLAIMER The opinion and conclusions expressed or implied in the report are those of the research agency. They are not necessarily those of the TRB, the National Research Council, AASHTO, or the U.S.

This study evaluates the effectiveness of state child safety seat laws in the United States. Data for all fifty states for the period 1975 to 1994 are used. Pooled time series analysis is employed to estimate a model of the rate of fatalities suffered by children ages 0-5 years as occupants in automobile crashes. The occupant fatality rate for children 6-11 years of age is used as a comparison group to control for other trends not introduced in the estimated models. The results show that child safety seat policies have significantly reduced fatality rates among children 0-5 years of age. For each additional year of age covered by a state statute, this fatality rate drops 4.8%. A similar reduction in the fatality rate of the older age cohort (6-11 years old) was not observed. 1 The Effectiveness of Child Safety Seat Laws in the Fifty States INTRODUCTION Injuries remain the leading cause of death among children in the United States, with motor vehicle accidents the most common source...

This preliminary research examines traffic safety variables that are influencing the behavior of interest groups in the European Union. Utilizing a fixed effects estimation model, this research identifies variables that are influencing traffic deaths in the 15 member states that made up the European Union prior to May 1, 2004. Time series data analyzing the impact of vehicle concentration in member states, unemployment, length of roadways, legal driving blood alcohol levels, speed on roadways, gross domestic product per capita, and alcohol consumption per capita are examined across time in these countries. Further research on this question will investigate how interest groups are altering the relationship between these variables and the dependent variable, traffic fatalities. In turn, future research will investigate the lobbying efforts of interest groups as they attempt to influence traffic safety policy in the European Union. 3Introduction As in most nations, traffic and transport safety is a major concern for the 27 member-states that constitute the European Union (EU). And, while policy makers, legislators, and interest groups have all worked to make transportation in Europe safer, more efficient, and environmentally more “green, ” serious issues remain for the EU and its member-states as it tries

Abstract: Using data on road accidents, traffic fatalities and driving offences taking place in Italy over the period 2001-2005, we estimate the effects of the introduction on July 2003 of a penalty point system for driving offences. To identify the causal effect of the penalty point system on road safety we use a Regression Discontinuity Design. It emerges that, controlling for weather conditions, police patrols, speed cameras, gasoline price, the introduction of the penalty point system has led to a reduction of about 10 % of road accidents and of about 25 % of traffic fatalities. These findings are robust to different specifications of the model and different time windows. Moreover, it emerges that the driving offences for which the introduction of the new regime has determined a sharp change in the sanction scheme have reacted more than offences for which the change was less relevant.

Abstract:This article, in reviewing the long-running US debate on speed limits, illustrates how a different valuation of the trade-off between private mobility needs and safety concerns can shape transport policies. It is argued that the regulatory decentralization debate, together with the speed limit in force in each state, obey the social preferences and valuation given to this trade-off. Such a view is consistent with evidence that higher speed limits are to be found in states with greater private mobility needs, even though their fatality rates might be among the highest in the country. By contrast, lower speed limits and supporters of a low national speed limit are to be found in states that show a greater concern for safety outcomes and which are less dependent on private mobility. By reviewing these events and examining the role played by the main actors and analyzing their motivations, the article identifies important lessons for similar future discussions on transport policy.

Abstract:This article, in reviewing the long-running US debate on speed limits, illustrates how a different valuation of the trade-off between private mobility needs and safety concerns can shape transport policies. It is argued that the regulatory decentralization debate, together with the speed limit in force in each state, obey the social preferences and valuation given to this trade-off. Such a view is consistent with evidence that higher speed limits are to be found in states with greater private mobility needs, even though their fatality rates might be among the highest in the country. By contrast, lower speed limits and supporters of a low national speed limit are to be found in states that show a greater concern for safety outcomes and which are less dependent on private mobility. By reviewing these events and examining the role played by the main actors and analyzing their motivations, the article identifies important lessons for similar future discussions on transport policy.