Speed Enforcement Research Articles

Speed enforcement in Norway: Testing a game-theoretic model of the interaction between drivers and the police

This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers and the police. This model makes predictions both about how drivers will adapt to changes in the amount of enforcement (the more enforcement, the less violations) as well as how the police will adapt to changes in the rate of violations (the less violations, the less enforcement). The paper attempts to test the game-theoretic model empirically. Testing the model rigorously is difficult, mainly because some of the relevant variables are not reliably measured and are endogenous. Two models were developed: one to identify sources of changes in the rate of violations, one to identify sources of changes in the amount of enforcement. The predictions of the game-theoretic model were supported, although the results were not statistically significant in the model of how the police adapt enforcement to changes in the rate of violations.

Optimal Mainline Variable Speed Limit Control to Improve Safety on Large‐Scale Freeway Segments

AbstractThe primary objective of this study was to develop a procedure for determining the optimal variable speed limit (VSL) control strategy that aims at reducing both collision risks and injury severity on large‐scale freeway segments. The achieved reduction in collision risks and injury severity were evaluated using real‐time crash risk and severity prediction models. A modified cell transmission model (CTM) that took into consideration the capacity drop and the stop‐and‐go traffic was used to simulate the traffic operations with the VSL control. A computational procedure that incorporated the genetic algorithm and the CTM was proposed for the optimization of critical VSL control factors. Three scenarios with various placements of VSL signs on freeway mainlines were evaluated. The results showed that the optimal VSL control successfully decreased the collision risks by 22.62% and reduced the injury severity of crashes by 14.67%. We also evaluated how drivers’ compliance to speed limits affected the effectiveness of VSL control. The safety effects decreased as drivers’ compliance rate to the VSL control decreased. The finding suggests the use of speed enforcement techniques together with the VSL control to achieve the optimum control effects.

Assessing specific deterrence effects of increased speeding penalties using four measures of recidivism

Traffic law enforcement sanctions can impact on road user behaviour through general and specific deterrence mechanisms. The manner in which specific deterrence can influence recidivist behaviour can be conceptualised in different ways. While any reduction in speeding will have road safety benefits, the ways in which a ‘reduction’ is determined deserves greater methodological attention and has implications for countermeasure evaluation more generally. The primary aim of this research was to assess the specific deterrent impact of penalty increases for speeding offences in Queensland, Australia, in 2003 on two cohorts of drivers detected for speeding prior to and after the penalty changes were investigated. Since the literature is relatively silent on how to assess recidivism in the speeding context, the secondary research aim was to contribute to the literature regarding ways to conceptualise and measure specific deterrence in the speeding context. We propose a novel way of operationalising four measures which reflect different ways in which a specific deterrence effect could be conceptualised: (1) the proportion of offenders who re-offended in the follow up period; (2) the overall frequency of re-offending in the follow up period; (3) the length of delay to re-offence among those who re-offended; and (4) the average number of re-offences during the follow up period among those who re-offended. Consistent with expectations, results suggested an absolute deterrent effect of penalty changes, as evidenced by significant reductions in the proportion of drivers who re-offended and the overall frequency of re-offending, although effect sizes were small. Contrary to expectations, however, there was no evidence of a marginal specific deterrent effect among those who re-offended, with a significant reduction in the length of time to re-offence and no significant change in the average number of offences committed. Additional exploratory analyses investigating potential influences of the severity of the index offence, offence history, and method of detection revealed mixed results. Access to additional data from various sources suggested that the main findings were not influenced by changes in speed enforcement activity, public awareness of penalty changes, or driving exposure during the study period. Study limitations and recommendations for future research are discussed with a view to promoting more extensive evaluations of penalty changes and better understanding of how such changes may impact on motorists’ perceptions of enforcement and sanctions, as well as on recidivist behaviour.

Safety and Headway Characteristics in Highway Work Zones with Automated Speed Enforcement

This paper investigated the headway distribution of platooning vehicles in work zones with and without automated Speed Photo Enforcement (SPE). Data from two work zones were collected and analyzed. The portion of vehicles traveling with a very short headway (less than 0.7 sec) was also examined. In addition, the behavior of vehicles near the law enforcement vehicles was analyzed in terms of applying brakes and changing lane in one of the work zones. The results indicated that the mean headway of cars in the median lane significantly increased in both work zones when the SPE van was present compared to the base condition. For trucks, the mean headway increase was significant only in the shoulder lane when the SPE was present. This is a beneficial effect and indicates that drivers had a longer time to react to the lead vehicles. It was also found that the proportion of cars traveling with a very short headway in the median lane significantly decreased when a SPE van was present at one work zone (I-64). In the shoulder lane, no very short headway was observed when SPE was implemented. The difference in braking behavior was not significant when SPE was compared to police car presence. However, lane changing behavior was significantly different for cars traveling in the median lane and also for trucks traveling in the shoulder lane. The proportion of cars changing lanes was 5 percent with a police car present and increased to 8 percent when the SPE van was present. A significant number of trucks changed lanes from the shoulder to the median when the police car was present to comply with state law.

Automated speed enforcement systems to reduce traffic-related injuries: closing the policy implementation gap

In the USA, traffic-related injuries are responsible for over 33 000 deaths each year1 and are the leading cause of death for individuals aged 1–24 years.2 Traffic-related injuries also take...

자유류 상태에서 고속도로 구간과속단속구간 및 대조구간 간의 교통류 특성 비교

무인과속단속시스템은 속도위반 차량을 효과적으로 단속하기 위해 도입되었으나, 기존의 지점 과속단속시스템의 경우 차량 내비게이션, 스마트폰 등을 통해 제공되는 위치정보 서비스로 인해 단속 효과가 현격히 낮아지게 되었다. 구간 과속단속시스템은 지점 과속단속카메라 설치 지점에서 나타나는 카메라 전후에서 급감속 및 재가속을 반복하는 회피 거동으로 인한 여러 가지 부정적인 문제점을 보완하기 위해 도입되어 설치를 확대해 나가고 있다. 이에 본 연구에서는, 국내 고속도로 상에 설치된 구간 과속단속시스템에서 나타나는 교통류 특성에 대해 대조 구간을 설정하여 비교 분석하였다. 이를 위해 구간의 특성 등을 고려하여, 중부내륙선, 대전-통영선, 영동선 내의 구간 과속단속 시행구간에 대해 VDS 검지기 데이터를 수집하였으며, 데이터필터링을 통해 비교분석에 용이한 조건을 설정하고 자유속도 상태에서의 교통류 특성을 분석하였다. 분석결과, 구간 과속단속구간 내에서는 대조 구간에 비해 속도 평균 및 속도 분산이 낮아지는 경향을 보였으며, 통계적 검정 방법을 이용하여 이를 확인하였다. The Korean government introduced an automated speed enforcement system (ASES), which uses traffic enforcement cameras, to counteract safety issues that are caused by speeding. As the information of the traffic enforcement camera locations is provided to the drivers via navigation systems and mobile applications in a timely manner, drivers can avoid enforcement by momentarily diminishing their speeds only near the camera locations. To prevent drivers' evasional behavior and improve the effectiveness of ASES, section control, which enforces speeding vehicles by measuring their average travel speeds over a stretch of road and checking against the speed limit, has been recently implemented. In this study, Section Speed Enforcement Zone and Comparison Zone are compared in terms of traffic stream characteristics under free flow conditions. To this end, loop detector data were obtained from the three study sites and analyzed. The study results demonstrated that drivers maintain their speeds below the speed limit over the enforcement section with a lower variance of speeds.

Enforcement avoidance behavior near automated speed enforcement areas in Korean expressways

Automated speed enforcement system (ASES) has been deployed as a safety countermeasure on Korean roadways to reduce speeding-related traffic crashes; information on ASES locations is mandated to be open to the public. However, because drivers are alerted about enforcement via on-board navigation systems and roadside signs, they can avoid enforcement by momentarily reducing their speeds near ASES locations. This enforcement avoidance behavior (EAB) can induce sudden changes in speed near the enforcement locations and thereby increase risk of crash occurrence.In light of this situation, the present study evaluates the effects of ASES on traffic behavior and safety. An analysis of traffic data shows that drivers indeed diminish their speeds near enforcement locations, and accelerate shortly after passing the locations. To investigate how this behavior affects safety performance, this study, by using Empirical Bayes analysis with comparison groups, compares crash occurrences along a certain section before and after the installation of ASES. The comparative analysis shows that overall crash occurrence dropped by 7.6% on average near the enforcement locations, although the reduction was not significant. However, an average 11% non-significant increase in crash occurrence is also observed in the upstream segment, where enforcement is announced to drivers and traffic starts to diminish speed.The findings suggest that the sudden changes in traffic speed induced by EAB substantially negate the benefits of ASES. Therefore, modification of the design of current ASES is required to mitigate EAB and further improve the effectiveness of ASES.

Overt vs. covert speed cameras in combination with delayed vs. immediate feedback to the offender

Speeding is a major problem in road safety because it increases both the probability of accidents and the severity of injuries if an accident occurs. Speed cameras are one of the most common speed enforcement tools. Most of the speed cameras around the world are overt, but there is evidence that this can cause a “kangaroo effect” in driving patterns. One suggested alternative to prevent this kangaroo effect is the use of covert cameras. Another issue relevant to the effect of enforcement countermeasures on speeding is the timing of the fine. There is general agreement on the importance of the immediacy of the punishment, however, in the context of speed limit enforcement, implementing such immediate punishment is difficult. An immediate feedback that mediates the delay between the speed violation and getting a ticket is one possible solution. This study examines combinations of concealment and the timing of the fine in operating speed cameras in order to evaluate the most effective one in terms of enforcing speed limits. Using a driving simulator, the driving performance of the following four experimental groups was tested: (1) overt cameras with delayed feedback, (2) overt cameras with immediate feedback, (3) covert cameras with delayed feedback, and (4) covert cameras with immediate feedback. Each of the 58 participants drove in the same scenario on three different days. The results showed that both median speed and speed variance were higher with overt than with covert cameras. Moreover, implementing a covert camera system along with immediate feedback was more conducive to drivers maintaining steady speeds at the permitted levels from the very beginning. Finally, both ‘overt cameras’ groups exhibit a kangaroo effect throughout the entire experiment. It can be concluded that an implementation strategy consisting of covert speed cameras combined with immediate feedback to the offender is potentially an optimal way to motivate drivers to maintain speeds at the speed limit.

Immense changes in traffic – Considerable stability in discourses. Road speed in Danish parliamentary documents 1900–2010

Research on road safety acknowledges speed as having a major impact on both the number and severity of road crashes, and this seems to have been translated into policies. However, a closer look reveals that the societal debate and political context also seem to play a major role in the way road safety policies are shaped. Yet, the knowledge on the political discourse regarding speeding and speed management is scarce. In this paper, we analyze the ways speed has been managed and legislated in transport policymaking by studying Danish parliamentary documents from 1903 through 2010. Analyzing the material qualitatively in two phases, first, we looked for notable policy shifts in the material, and consequently identified five historical periods. Second, we analyzed these periods in more detail, and identified and analyzed four repetitive discourses about speed across them, which were as follows: speed, individual rights and responsibilities; speed and safety; speed, policy measures, and law enforcement; and speed and other societal goals. While the transport system has undergone a massive change during the last 100 years, we found a considerable stability in the discourses regarding speed policies. The themes and patterns we distinguished in the documents occurred repeatedly. Certain discourses are strongly connected to the way speed is discussed and governed, and these are likely to emerge when speed policies are taken up in the parliamentary context. We conclude that in addition to the current prominent discourses, past discourses may have a strong influence on the way safety measures and policies are being understood and accepted.

Point-to-point speed enforcement systems: Speed limits design criteria and analysis of drivers’ compliance

Point-to-point (P2P) speed enforcement is a relatively new approach to traffic law enforcement. Its technology allows vehicles whose average speed exceeds the speed limit over the controlled section to be fined. It therefore encourages compliance over distances longer than those where spot enforcement policies have been in place.In this paper, a procedure for consistently setting speed limits with such enforcement systems is proposed. Such a method has been applied to design the speed limits on two motorways in the district of Naples, Italy, where P2P enforcement systems became operational in 2009 and 2010. The speed limits, which were set using the Italian geometric design standard to assess vehicle stability and stopping sight distance, have been compared with those provided by using well-known international standards.The impact of the newly designed speed limits and of the P2P enforcement system on drivers’ speeding behaviour has been quantified for each highway section and vehicle type. In fact, accurate measurements of the average travel speeds of each vehicle crossing the enforced sections, before and after the activation of the system, were available. The migration from the old speed limits with spot speed enforcement to the new approach resulted in a notable increase in drivers’ compliance to the speed limits with a remarkable decrease in both the average of individual speeds and in their standard deviation.In addition, the analysis of 3years of data shows that a gradual adaptation of drivers’ behaviour to the system took place. In particular, a decreasing compliance to the speed limits points to a non-optimal system management. Finally, the results of a revealed preference survey allowed us to make a behavioural interpretation regarding the significantly different impacts measured on the two motorways.

Before-and-After Empirical Bayes Evaluation of Automated Mobile Speed Enforcement on Urban Arterial Roads

Speeding is a leading factor in road collisions and is found to contribute to approximately one-third of all fatal collisions. Speed enforcement is one of the most common countermeasures used to reduce speed. However, a gap exists in the literature regarding the effectiveness of automated mobile photo enforcement on urban arterial roads. This study addresses this gap using the before-and-after empirical Bayes method to account for regression to the mean effects and other confounding factors. Locally developed safety performance functions and yearly calibration factors for different collision severities were obtained by using a reference group of urban arterial roads. The evaluation period covers 8 years. Collision records, deployment information, traffic counts, and road geometric data were collected. The results showed consistent reductions in different collision severities; the reductions ranged from 14% to 20%, with the highest reductions observed for severe collisions. The enforced segments were further categorized according to site selection criteria and deployment hours to examine the effect of enforcement on collision reduction. More reductions were found at segments that had more collisions during the before period and longer deployment hours. The study also compared the safety effects of continuous and discontinuous enforcement strategies on different arterials, and the analysis revealed that continuous enforcement achieved more reductions across all severities and types of collisions. The study also investigated the spillover effects on adjacent unenforced approaches. Significant reductions were found, and these results are discussed with regard to the general and specific deterrence of the enforcement.

Effects on speed and safety of point-to-point speed enforcement systems: Evaluation on the urban motorway A56 Tangenziale di Napoli

In this paper, we evaluated the effects on speed and safety of the point-to-point (P2P) speed enforcement system activated on the urban motorway A56 in Italy. The P2P speed enforcement is a relatively new approach to traffic law enforcement that involves the calculation of the average speed over a section. To evaluate the speed effects, we performed a before–after analysis of speed data investigating also effects on non-compliance to speed limits. To evaluate the safety effects, we carried out an empirical Bayes observational before-and-after study.The P2P system led to very positive effects on both speed and safety. As far as the effects on the section average travel speeds, the system yielded to a reduction in the mean speed, the 85th percentile speed, the standard deviation of speed, and the proportion of drivers exceeding the speed limits, exceeding the speed limits more than 10km/h, and exceeding the speed limits more than 20km/h. The best results were the decrease of the speed variability and the reduction of the excessive speeding behaviour. The decrease in the standard deviation of speed was 26% while the proportion of light and heavy vehicles exceeding the speed limits more than 20km/h was reduced respectively by 84 and 77%.As far as the safety effects, the P2P system yielded to a 32% reduction in the total crashes, with a lower 95% confidence limit of the estimate equal to 22%. The greatest crash reductions were in rainy weather (57%), on wet pavement (51%), on curves (49%), for single vehicle crashes (44%), and for injury crashes (37%). It is noteworthy that the system produced a statistically significant reduction of 21% in total crashes also in the part of the motorway where it was not activated, thus generating a significant spillover effect.The investigation of the effects of the P2P system on speed and safety over time allowed to develop crash modification functions where the relationship between crash modification factors and speed parameters (mean speed, 85th percentile speed, and standard deviation of speed) was expressed by a power function. Crash modification functions show that the effect of speed on safety is greater on curves and for injury crashes.Even though the study results show excellent outcomes, we must point out that the crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time. To maintain its effectiveness over time, P2P speed enforcement must be actively managed, i.e. constantly monitored and supported by appropriate sanctions.

Freeway Lab: Testing Dynamic Speed Limits

This paper presents the Dynamic Speed Limit (DSL) experiment that took place in June 2013 on the last 13 km stretch of the B-23 freeway accessing the city of Barcelona (Spain). The DSL system installed on that freeway in addition to the high density of surveillance equipment available makes this stretch a suitable highway lab. The objective of the experiment was to construct a comprehensive database of traffic engineering variables on a freeway site when different speed limits apply. Special attention was paid to ensure similar demand conditions between different scenarios. The experiment included the modification of the speed limits on a freeway segment making use of dynamic signals. Detailed measurements of vehicle counts, speeds, occupancies, lane changing maneuvers and travel times were taken. These simultaneous measurements obtained from very different types of monitoring equipment have been grouped into a single database. These include measurements from inductive loop detectors, radar, ultrasound and passive infrared non-intrusive traffic detectors, TV cameras and license plate recognition devices. The potential of this multi-source database is huge. For instance, a preliminary analysis empirically proves that drivers’ compliance with dynamic speed limits is very limited, unless speed enforcement devices are present. In addition, it is also proved that lane changing rates increase together with the occupancy level of the freeway. This comprehensive DSL database, unique in its nature, is made publicly available to the whole research community [Link], [1] in order to use up all its information. The present paper aims to present in detail this DSL experiment and its preliminary results and to contribute in the dissemination of the resulting database. This will facilitate its analysis to any interested researcher, and would lead to a better understanding of the causes and effects of DSL strategies on freeways.

Rapid assessment of road safety policy change: relaxation of the national speed enforcement law in Russia leads to large increases in the prevalence of speeding

Reducing vehicle speed is among the most effective road safety strategies. We assess how a new policy in Russia that eliminates fines for driving up to 20 km/h above the...

An Interview With Mr. Sachin Bhatia

Sachin Bhatia, founder and CEO of Metro Infrasys Pvt. Ltd, is an engineer by qualification. He has worked in more than 20 tolling projects comprising of more than 300 lanes over the past decade. Sachin is always on the lookout for developing new technologies for more innovative and advanced solutions for highway and urban traffic and parking controls. He has also been an active speaker in a number of international conferences.Metro Infrasys Pvt. Ltd., headquartered in New Delhi, India, is an emerging expert technology provider in the field of intelligent transportation systems. The company has its service, integration, and development center at IMT Manesar, Gurgaon, India. Through state-of-the-art simulation techniques by employing mock lanes, the company incorporates diverse technologies to implement tolling, traffic management, and parking. Metro Infrasys adapts world-class business technologies with local knowledge and expertise to suit India’s environmental and operational conditions. The company collaborates with international technology-oriented organizations such as IBM, Kapsch, etc. In ITES, Metro Infrasys deals with highway intelligent transportation system (such as toll management system, highway traffic management system, weigh-in-motion, check-post, etc.) and urban intelligent transportation system (such as traffic enforcement-red light and speed enforcement system, parking management and guidance system, etc.). The company also operates offices in the United States.

The analysis of implementation possibilities of sectorial automated vehicle speed control systems on the roads of Lithuania

Excess speed is one of the largest road safety problems causing the increased risk of road crashes. A wide range of safety improvement measures, both educational and engineering, are being implemented to solve this problem. The main objective of those measures is to force vehicle drivers to observe the speed limit requirements and to ensure enforcement of speed requirements. This paper gives an overview of the impact of vehicle speeds on road safety and the effect of safety improvement measures. Possibilities for the implementation of sectorial vehicle speed enforcement system on the roads of national significance of Lithuania are presented. The paper contains criteria for the selection of road sections of Lithuania where the sectorial vehicle speed enforcement system (speed cameras) could be installed. The amount of investments is also given necessary for the installation of sectorial vehicle speed enforcement system on the selected road sections as well as their one-year maintenance. Taking into consideration the damage incurred by the country due to the people killed on roads a pay-back period of the sectorial vehicle speed enforcement system is determined.

On the road to prevention: road injury and health promotion.

Road traffic injuries are already the leading cause of injury mortality and morbidity globally and by 2030 are predicted to be the fifth leading cause of mortality in the world. Australia has seen a dramatic reduction in road deaths and serious injuries since the 1970s and holds an international reputation for road traffic injury prevention due, in part, to its success in pioneering the multidisciplinary and intersectoral approach needed to address this significant issue and by applying an evidence-led approach to policy development. The paper will discuss Australia's early success in road traffic injury prevention (road safety), particularly the achievements following the implementation of targeted programs that focussed on road user behaviours for which health promotion played a role. The most successful of these programs was the introduction of comprehensive seat belt laws, random breath testing and more recently, strategic speed enforcement programs. Amid an array of significant challenges faced by the transport system in the future, the rapid development in information and communication technologies applied to transport is likely to provide the next generation of road safety benefits. The potential for a semi-autonomous transport system is likely to provide the next significant decline in road fatalities and serious injuries over the next 2 decades and the role of health promotion in relation to raising community engagement and building coalitions to increase uptake of new technologies will be discussed.

Why is road safety in the U.S. not on par with Sweden, the U.K., and the Netherlands? Lessons to be learned

This study compared road safety and related factors in the U.S. with those in Sweden, the United Kingdom, and the Netherlands (which are among the best-performing countries), in order to identify actions most likely to produce casualty reductions in the U.S. The reviewed topics were basic country statistics, road fatalities and various fatality rates, and selected road-safety issues. The main differences concerned structural and cultural factors (such as vehicle distance driven), and procedural factors (such as alcohol-impaired driving, exceeding speed limits, and use of seat belts). The main recommendations for improving road safety in the U.S. are as follows: (1) lower states’ BAC limits, and encourage the use of alcohol ignition interlocks (2) reexamine the current speed-limit policies and improve speed enforcement, (3) implement primary seat-belt-wearing laws in each state that would cover both front and rear occupants, and reward vehicle manufacturers for installation of advanced seat-belt reminders, and (4) reconsider road-safety target setting so that the focus is on reducing fatalities and not on reducing fatality rate per distance driven, and (5) consider new strategies to reduce vehicle distance driven.

The Automated Speed Enforcement System — A Case Study in Putrajaya

Speeding contributed 60% of road crashes in Malaysia every year. The automated speed enforcement (ASE) system was piloted in 10 black spots areas across the states of Selangor, Perak, Kuala Lumpur and Putrajaya on 22 September 2012. This study was aimed to measure the drivers’ speed compliance at Lebuh Sentosa, Putrajaya where ASE camera was installed. Spot-speed studies conducted in October, November 2012 and February 2013, respectively revealed more than 70-90% compliance at the treatment site (ASE camera installed). However, less than 50% of drivers comply with the speed limit at the control site (ASE camera not installed). At treatment site, the 85th percentile speed was less than 70 km/h but it was above 70 km/h at the control site. Moreover, the authors found that the effect of the ASE camera increases over the time. This implies that the ASE system has successfully reduced the speeding incidents at the black spot area.

An Online Self-Learning Algorithm for License Plate Matching

License plate recognition (LPR) technology is a mature yet imperfect technology used for automated toll collection and speed enforcement. The portion of license plates that can be correctly recognized and matched at two separate stations is typically in the range of 35% or less. Existing methods for improving the matching of plates recognized by LPR units rely on intensive manual data reduction, such that the misread plates are manually entered into the system. Recently, an advanced matching technique that combines Bayesian probability and Levenshtein text-mining techniques was proposed to increase the accuracy of automated license plate matching. The key component of this method is what we called the association matrix, which contains the conditional probabilities of observing one character at one station for a given observed character at another station. However, the estimation of the association matrix relies on the manually extracted ground truth of a large number of plates, which is a cumbersome and tedious process. To overcome this drawback, in this study, we propose an ingenious novel self-learning algorithm that eliminates the need for extracting ground truth manually. These automatically learned association matrices are found to perform well in the correctness in plate matching, in comparison with those generated from the painstaking manual method. Furthermore, these automatically learned association matrices outperform their manual counterparts in reducing false matching rates. The automatic self-learning method is also cheaper and easier to implement and continues to improve and correct itself over time.