Road Safety Benefits Research Articles

Truck drivers’ views on the road safety benefits of advanced driver assistance systems and Intelligent Transport Systems in Tanzania

Truck drivers’ views on the road safety benefits of advanced driver assistance systems and Intelligent Transport Systems in Tanzania

Assessment of Intelligent Unmanned Maintenance Construction for Asphalt Pavement Based on Fuzzy Comprehensive Evaluation and Analytical Hierarchy Process

Conventional human-involved maintenance methods for asphalt pavement pose significant challenges when applied to high-traffic road sections, often leading to congestion and safety risks, as well as reduced maintenance efficiency. In recent years, explorations into unmanned construction technology for newly constructed expressways have yielded beneficial and encouraging results. However, its application in road maintenance in more complex environments still needs to be expanded. In this study, an intelligent unmanned maintenance technology for asphalt pavement was applied to the Lilong Highway in Zhejiang Province, China, and the compactability, thickness, surface smoothness, permeability coefficient, and constructure depth of maintenance road sections were measured. Then, based on fuzzy comprehensive mathematics and the analytic hierarchy process, a comprehensive evaluation was performed on the intelligent unmanned maintenance technology, considering the aspects of road quality, safety, application, and socio-economic benefits. The results show that the road quality of intelligent unmanned maintenance technology can meet the road specification requirements. In addition, the membership degree of unmanned maintenance technology in the excellent grade is the highest, reaching 0.805, and the quantified value for the overall evaluation of the application effectiveness of unmanned maintenance technology is 92.10. This means that the final comprehensive evaluation result of unmanned maintenance technology is rated as excellent. The research findings provide decision-makers with valuable insights into the unmanned automation maintenance challenges faced by asphalt pavement, enabling them to implement appropriate measures to elevate the maintenance standards of road transportation.

Review Paper on Speed Reduction Methods to Promote Road Safety and to Save Lives

Abstract: The traditional and important road safety benefits of lower vehicle speeds include saving lives and reducing the impact and likelihood of crashes. However, speed reduction has important additional benefits that increase the quality of life for neighborhoods and bigger urban areas, but also for society at large. Speed reduction measures fall into the categories: direct – infrastructure, vehicle technology and enforcement and indirect – signage, education and publicity. Similar a small decrease in average vehicle speed across a road network will lead to a considerable reduction in traffic fatalities and the severity of injuries. In this paper, study was carried out on types of speed reduction infrastructure and their utility to reduce the speed of vehicle. High Speed of vehicle get uncontrolled on curve, so in this paper more attention given to application of speed reducer infrastructure on curve.

Road safety benefits and challenges associated with pedestrian footbridge patronage along the Madina-Adenta highway

ABSTRACT Pedestrian fatalities constitute a fourth of all road deaths in Ghana. Footbridges are recent countermeasures deployed to improve pedestrians’ safety in Ghana. The main objectives of the research were to: (i) identify the lapses on the footbridges and their effects on pedestrian crossing behavior in the vicinity of the edifices, (ii) explore the reasons why pedestrians do not use the footbridges and, (iii) evaluate the road safety impact of the footbridges on pedestrian safety. Naturalistic observations and peak-hour pedestrian counts on the footbridges and within the vicinities of the facilities were carried out. Focus group discussions were also conducted to understand pedestrian crossing and walking behavior at the footbridges. Lastly, pedestrian casualties were analyzed for 3 years before and after the bridge construction. There were 165 pedestrian casualties along the highway section. Of these, 29% were fatal while 40% of the victims were hospitalized for at least 24-hours. Many pedestrians still cross the multilane-highway at grade. The main reasons for non-use of the bridges include heights, lengths, security, poor illumination and hawking. Pedestrian injuries have significantly declined during the after period compared with the before period. Findings have implications for road safety education and siting of future footbridges.

On the road safety benefits of advanced driver assistance systems in different driving contexts

Advanced Driver Assistance Systems (ADAS) have introduced several benefits in the vehicular industry, and their proliferation presents potential opportunities to decrease road accidents. The reasons are mainly attributed to the enhanced perception of the driving environment and reduced human errors. However, as environmental and infrastructural conditions influence the performance of ADAS, the estimation of accident reductions varies across geographical regions. This study presents an interdisciplinary methodology that integrates the literature on advanced driving technologies and road safety to quantify the expected impact of ADAS on accident reduction across combinations of road types, lighting, and weather conditions. The paper investigates the safety effectiveness of ADAS and the distribution of frequency and severity of road accidents across 18 driving contexts and eight accident types. Using road safety reports from the United Kingdom (UK), it is found that a high concentration of accidents (77%) occurs within a small subset of contextual conditions (4 out of 18) and that the most severe accidents happen in dark conditions on rural roads or motorways. The results of the safety effectiveness analysis show that a full deployment of the six most common ADAS would reduce the road accident frequency in the UK by 23.8%, representing an annual decrease of 18,925 accidents. The results also show that the most frequent accident contexts, urban-clear-daylight and rural-clear-daylight, can be reduced by 29%, avoiding 7,020 and 3,472 accidents, respectively. Automatic Emergency Braking (AEB) is the most impactful technology, reducing three out of the four most frequent accident categories – intersection (by 28%), rear-end (by 27.7%), and pedestrian accidents (by 28.4%). This study helps prioritise resources in ADAS research and development focusing on the most relevant contexts to reduce the frequency and severity of road accidents. Furthermore, the identified contextual accident hotspots can assist road safety stakeholders in risk mitigation programs.

Correlation between oral fluid and blood THC concentration: A systematic review and discussion of policy implications

Cannabis is the second most commonly used impairing substance by drivers, after alcohol. As more countries legalize cannabis, there is concern that cannabis-impaired driving will increase. In many countries, police use roadside devices to test for oral fluid THC (the primary psychotropic component in cannabis) to identify drivers who used cannabis; including in countries with non-zero per se limits for THC in blood. This practice is questioned as previous research demonstrates a poor correlation between oral fluid and blood THC concentrations at the individual level.We conducted a meta-analysis to identify all research that compared oral fluid with blood THC levels. We obtained individual-level data from study authors and analyzed pooled individual-level data to calculate sensitivity and specificity of oral fluid THC (at various cut-off values) to detect blood THC above different concentration limits. Finally, we explored practical implications of using oral fluid THC in an enforcement context.Our review found THC concentrations measured in over 18,000 paired samples of oral fluid and blood. We found a good correlation between the presence of THC in oral fluid and presence of THC in blood (sensitivity = 71.2%, specificity = 97.7%). However oral fluid THC, at commonly used cut-off values, is less sensitive and less specific when used as a biomarker to detect people with blood THC concentrations above commonly used per se limits (such as 5 ng/mL). As such, there will be a large number of “false positive” tests if oral fluid THC testing were used as a biomarker for “illegal” THC concentrations in randomly selected drivers. We argue that the adverse implications of false positive oral fluid THC tests in this context outweigh the possible road safety benefits and we recommend against oral fluid THC screening in randomly selected drivers in countries with non-zero per se limits for blood THC. In contrast, oral fluid THC tests appear to be useful for investigating “high-risk” drivers who come to police attention because of evidence of impairment.

Tweeting about twenty: an analysis of interest, public sentiments and opinion about 20mph speed restrictions in two UK cities

BackgroundTwenty miles per hour (20mph) speed limits (equivalent to roughly 30kmh) have become part of public health policies to reduce urban road collisions and casualties, especially in Western countries. Public opinion plays a crucial role in opposition to and acceptance of policies that are advocated for improving public health. Twenty miles per hour speed limit policies were implemented in Edinburgh and Belfast from 2016 to 2018. In this paper, we extract public opinion and sentiments expressed about the new 20mph speed limits in those cities using publicly available Twitter data.MethodsWe analysed public sentiments from Twitter data and classified the public comments in plain English into the categories ‘positive’, ‘neutral’, and ‘negative’. We also explored the frequency and sources of the tweets.ResultsThe total volume of tweets was higher for Edinburgh than for Belfast, but the volume of tweets followed a similar pattern, peaking around 2016, which is when the schemes were implemented. Overall, the tone of the tweets was positive or neutral towards the implementation of the speed limit policies. This finding was surprising as there is a perception among policymakers that there would have been public backlash against these sorts of policy changes. The commonly used hashtags focused largely on road safety and other potential benefits, for example to air pollution.ConclusionsOverall, public attitudes towards the policies were positive, thus policymakers should be less anxious about potential public backlash when considering the scale-up of 20mph speed restrictions.

Highway concessions and road safety:Evidence from Brazil

Reducing road fatalities is a key policy goal in several countries and there is a vast literature on what factors affect road safety performance. Nonetheless, there is limited evidence on whether highway concessions and Public Private Partnerships (PPP) can bring road safety benefits, despite the growing number of countries adopting this type of policy to finance and manage road infrastructure. In this paper, we use a difference-in-differences approach to examine the causal effect of highway concessions on road safety outcomes using daily data from Brazilian Federal highways over 11 years between 2007 and 2017. We exploit the transition from public to private management in some but not all Brazilian states to provide both within- and between-states comparison. We find that concessions promote a small but significant reduction in the number and fatality of road crashes as well as and the number of people and vehicles involved in crashes. Between 2007 and 2017, procured roads had on average 16 fewer deaths then publicly managed highways for every 1000 crashes each year. These road safety benefits only become statistically significant a few years after a concession implementation, but they are marginally larger for every additional year of concession. Finally, our results suggest that including safety-based incentives in concession contracts can substantially improve road safety performance. The findings of the paper have important implications for the social and economic evaluation of road concessions and for road infrastructure policy more broadly.

Evaluation of the effectiveness of vehicle roll stability control (RSC) for high center of gravity light passenger vehicles in Australasia

Objective Rollover crashes, which occur when the vehicle’s side or roof makes impact with the ground, present particularly serious injury risk. Higher rollover risk has been found for high riding vehicles – those with a relatively high center of gravity compared to the width of the wheel track. Electronic Stability Control (ESC), which automatically applies brakes to individual wheels and reduces engine power to help drivers regain control when traction is lost, has been shown to be effective in preventing a proportion of rollovers. A newer safety technology, Roll Stability Control (RSC), uses similar technology aimed specifically to reduce rollover risk. This study sought to estimate rollover crash rates associated with the fitment of RSC compared to non-fitment for high center of gravity (CG) light passenger vehicles using an induced exposure analysis. Methods Police-recorded Australasian crash data were studied for the years 2008-2017. A quasi-induced exposure analysis was restricted to vehicles already equipped with ESC as vehicles fitted with RSC always have ESC fitted. Rollover risk associated with RSC fitment was assessed, controlling for year of crash, speed limit at crash location, year of vehicle manufacture, vehicle market group, driver age, driver gender and jurisdiction identifier. Results The analysis found a statistically significant rollover risk ratio of 0.76 (95% CI 0.62-0.93), representing a 24% reduction in rollover risk, associated with RSC fitment for vehicles manufactured between 2008 and 2017. Analysis by particular market groups found significant risk ratio reductions for commercial utilities and large SUVs, but not for the other high CG market groups individually. Conclusions These results suggest that RSC is a highly effective safety feature for high CG vehicles. Fleet data from Australia and New Zealand showed declining rates of RSC fitment over recent years for SUVs, meaning the potential road safety benefits of the technology are not being fully realized.

Addressing the awareness gap: A combined survey and vehicle registration analysis to assess car owners’ usage of ADAS in fleets

Now Advanced Driver Assistant Systems (ADAS) have entered the consumer market policymakers need instruments to monitor not only the amount of ADAS-equipped cars but also whether car owners actually use these systems; a prerequisite for many ADAS to achieve road safety and/or CO2 reduction benefits. Although questionnaires provide the most common method for large scale fleet assessment, current questionnaires fall short in their ability to assess ADAS usage. Their main pitfall is that ADAS ownership – necessary to compute the gap between ADAS ownership and usage – is based on self-reported rather than actual ADAS ownership. In other words, it is implicitly presumed that car owners are aware of the ADAS with which their car is, or is not, equipped. To our knowledge, the presumption of awareness of ADAS ownership has not been acknowledged as a limitation in current questionnaire-based studies on ADAS usage. Therefore, this paper presents a methodology to address the awareness gap by combining survey and vehicle registration analysis to assess car owners’ usage of ADAS in fleets. In this method, ADAS awareness constitutes of the difference between ADAS presence based on self-report and ADAS presence based on the vehicle specifications of participants’ own car (obtained through participants’ licence plate registration number). To test both the assumption that an awareness gap exists for ADAS as well as the feasibility of the method itself, a survey was performed under 1355 Dutch business drivers. It involved ADAS such as Adaptive Cruise Control, Lane Departure Warning and Emergency Brake. The study showed that many business drivers were unaware of with which ADAS their car is equipped and as a result, they were unable to report they own the ADAS concerned. However, drivers aware of owning a specific system generally reported that they use it. Additionally, the study revealed another group of participants: those who stated owning a specific ADAS while their vehicle specifications contradict this. In conclusion, awareness of ADAS ownership constitutes an important link that is currently missing when concatenating market penetration studies and regular questionnaires on ADAS usage. The proposed method may overcome this shortcoming, increase the validity of surveys on ADAS usage and provide large scale insights in the use of ADAS throughout an entire fleet of vehicles.

Detecting Driver’s Fatigue, Distraction and Activity Using a Non-Intrusive Ai-Based Monitoring System

Abstract The lack of attention during the driving task is considered as a major risk factor for fatal road accidents around the world. Despite the ever-growing trend for autonomous driving which promises to bring greater road-safety benefits, the fact is today’s vehicles still only feature partial and conditional automation, demanding frequent driver action. Moreover, the monotony of such a scenario may induce fatigue or distraction, reducing driver awareness and impairing the regain of the vehicle’s control. To address this challenge, we introduce a non-intrusive system to monitor the driver in terms of fatigue, distraction, and activity. The proposed system explores state-of-the-art sensors, as well as machine learning algorithms for data extraction and modeling. In the domain of fatigue supervision, we propose a feature set that considers the vehicle’s automation level. In terms of distraction assessment, the contributions concern (i) a holistic system that covers the full range of driver distraction types and (ii) a monitoring unit that predicts the driver activity causing the faulty behavior. By comparing the performance of Support Vector Machines against Decision Trees, conducted experiments indicated that our system can predict the driver’s state with an accuracy ranging from 89% to 93%.

The impact of changes to the NSW graduated driver licensing system on subsequent crash and offense experience

Introduction: In mid-2007 the State of New South Wales (NSW) in Australia introduced modifications to the existing graduated driver licensing system, lengthening the mandatory number of supervised hours for learner drivers aged under 25 years from 50 to 120 and extending the minimum learner period from 6 to 12 months. Additional driving restrictions were also introduced for young drivers in the two provisional licensed periods, P1, P2. This paper aims to evaluate this change by comparing the crash and offense experiences of young learner drivers before and after it occurred. Method: From driver licensing files supplied by the NSW transport authority two cohorts of persons obtaining their initial learner's permits in the year prior to the changes and in the subsequent year were constructed with demographic data, dates of transition to the driving phases, dates of crashes, and dates and types of traffic offenses. Both cohorts comprised around 100,000 individuals. Crash rates per 100 years of person-time under observation post P1 with their standard errors were calculated. Using a survival-analytic approach the proportion of crashes of all types were graphed in three month periods post P1. Sexes were treated separately as were initial learner ages of 16, 17, 18–21, and 22–24 years. The distribution of traffic offense types during P1 and P2 phases were also compared. With such large numbers formal statistical testing was avoided. Results: No meaningful differences in the crash or offense experiences of the two cohorts in either sex or at any age were observed. Delaying progress to unsupervised driving has road safety benefits. Conclusions: At least in conditions similar to those in NSW, requiring more than 50 h of supervised driving seems to have few road safety benefits. Practical applications: Licensing authorities should be cautious in extending the mandated number of supervised driving hours beyond 50.

Mapping and Deep Analysis of Vehicle-to-Infrastructure Communication Systems: Coherent Taxonomy, Datasets, Evaluation and Performance Measurements, Motivations, Open Challenges, Recommendations, and Methodological Aspects

The vehicle-to-infrastructure (V2I) communication system allows the exchange of information between vehicles and road infrastructures. It aims to avoid or reduce vehicular accidents, increase mobility, and provide other road safety benefits. This paper aimed to review and analyze the literature on data exchanges in the V2I communication system. The factors considered to improve the understanding of various contextual aspects and the characteristics of the field were motivations, open challenges, and recommendations from other researchers. We systematically searched all articles on data exchanges in the V2I communication system from the three main databases, namely ScienceDirect, Web of Science, and IEEE Xplore, from 2008 to 2018. These indices were sufficiently extensive to encompass our field of literature. A total of 70 articles were selected based on our inclusion and exclusion criteria. Most studies (42/70) covered a developed V2I communication system, while numerous articles (22/70) focused on general research on the V2I communication system. The smallest portion of articles (6/70) comprised reviews and surveys. The V2I system plays a key role in vehicular ad hoc networks but is less implemented than vehicle-to-vehicle communication owing to its deployment costs and maintenance requirements. However, numerous studies have been conducted on the V2I communication system to promote its utility. Research areas on V2I communication classification vary but are all equally vital. We expect this systematic review to help emphasize current research opportunities and thus extend and create additional research fields.

Assessing Effects of Transit Signal Priority on Traffic Safety: Empirical Bayes Before–After Study using King County, Washington, Data

Transit signal priority (TSP) has become popular among cities in the United States as a transit preferential treatment that improves transit operational performance through adjusting signal timing when transit vehicles are approaching signalized intersections. The majority of attention has been given to the operational effects of TSP. A small number of prior studies have discussed such a system’s effects on traffic safety, with few studies investigating North American implementations. Prior assessment results were mixed, leaving the understanding of TSP’s safety effects unclear. The purpose of this study was to add to the existing research on this topic, and to get a better understanding of TSP’s safety effects. An empirical Bayes (EB) before–after analysis was carried out using TSP implementation data from King County, Washington. Eleven transit corridors having had TSP activated in 2010–2014 were assessed, and 75 street sections without TSP treatment were selected to form a reference group. The EB analysis results showed a 13% reduction in total crashes with the implementation of TSP, a 16% reduction in property-damage-only crashes, and a 5% reduction in fatal and injury crashes. These results are consistent with most existing TSP safety studies. The study implies that TSP brings road safety benefits to transit corridors in a U.S. metropolitan setting, and suggests that transportation and transit agencies add safety assessment into future TSP practices.

Improving compliance with medical fitness to drive reviews: The role of behaviourally-optimised letters

To manage the increased crash risk posed by drivers with medical conditions and impairments, many licensing authorities ask high-risk drivers to undergo medical fitness to drive assessments. Maximising drivers’ compliance and satisfaction with these assessments is an ongoing challenge for these authorities. This study tested whether drivers’ compliance and satisfaction with a licensing authority’s request to provide a medical report could be improved by incorporating two applied behaviour change principles – simplified messaging and procedural fairness – into the authority’s request letter. Drivers undergoing medical review (N = 876) were assigned to receive either a standard request letter currently used by the authority, or a revised letter that incorporated simplified messaging and procedural fairness amendments. Drivers who received the revised letter were significantly more likely to submit a medical report by the due date. Additionally, of the drivers who submitted the report, those who received the revised letter submitted the report an average of four days faster than those who received the standard letter. These findings demonstrate that optimising letters using behavioural principles can improve compliance with licensing authorities’ requests, resulting in substantial time and cost savings for licensing authorities, possible road safety benefits, and potential reductions in the number of licences suspended for failure to provide a report.

Impact of daylight saving time on road traffic collision risk: a systematic review

BackgroundBills have been put forward in the UK and Republic of Ireland proposing a move to Central European Time (CET). Proponents argue that such a change will have benefits for...

Simulation and analysis of traffic flow for traffic calming

This paper evaluates the use of traffic calming as an option to address the high road casualties caused by speeding in Iran. The aim is to reduce the speed of motor vehicles to improve road safety and the quality of life. In this study, a part of Shahrara Street in Tehran that has speed humps installed is modelled in Aimsun software. The results suggest that calming the street leads to the reduced speed of vehicles and traffic volume on that street. However, it also results in reduced capacity of the street; thus, calming devices, including speed humps, should be placed at appropriate distances to each other to achieve an appropriate overall level of service, balancing speed and road safety benefits against capacity. In this research, a distance between speed humps of between 200 and 400 m is recommended.

Traffic medicine and road safety: The Australian perspective

International statistics show that Australia is one of the top 10 countries in terms of road crashes per 100,000 population. In spite of this, four people are killed and 90 seriously injured every day on Australian roads. In 2011, the Australian Transport and Infrastructure Council released a National Road Safety Strategy (NRSS) for Australia, calling for a reduction of at least 30 percent of deaths and serious injuries on our roads by the year 2020. The strategy is based on Safe System principles embracing the principle that in the longer term, no person should be killed or seriously injured on Australian roads. It accepts that people using the road network will inevitably make mistakes and that the road system must be more forgiving of these errors. It relies on better management of crash energy within the system to keep this within human tolerance. This adherence to what is generally known as Vision Zero aligns Australia with international best practice. To help achieve the immediate goal outlined in the strategy, a National Road Safety Action Plan (NRSAP) was recently adopted for the first three years from 2015 to 2017 focusing on four key areas – Safe Roads; Safe Speeds; Safe Vehicles; and Safe People. The action plan is focused on national efforts and activities to achieve long-term and permanent reductions in road trauma in line with the NRSS target. It aims to achieve these improvements through strategic investment in infrastructure and vehicle safety initiatives using best practice and capacity building as shown below: 1.Safe Roads: The plan calls for short- and long-term initiatives for road improvements based on best available evidence on road authorities at all government levels is necessary to ensure that Safe System principles are applied to all new road projects. 2.Safe Vehicles: Comprehensive regulatory and consumer tests are called for to ensure that proven safety design features and technologies are mandated in new Australian vehicles as quickly as possible. 3.Safe Speeds: Speed enforcement has been shown to be an effective management tool against speed-related crashes. The plan calls for a number of initiatives aimed at reducing speed-related risk. 4.Safe People: Various initiatives were outlined to improved driver and rider risk such as supervised learner driving hours, provisional licence periods, passenger night time restrictions, sanctions for speed and alcohol offences, and mobile phone bans. The strategy notes that there is potential to achieve large and lasting road safety benefits for all Australians, providing there is significant commitment by government and non-governments in implementing the actions outlined. If the strategy is to be successful, it will be necessary to maintain this trend in fatal and serious injury improvements, achieving a target of around 860 deaths and associated serious injuries by 2020. It will be quite a challenge to maintain this trend over this decade but clearly important in terms of road trauma improvement in Australia. Disclaimer: The views expressed in this paper are those of the author and do not necessarily reflect those of the Australian Transport and Infrastructure Council, its partners, and Monash University.

Embedding the Safe System into the next generation of road safety audits

Road Safety Audits are used to identify risks and to propose remedial works on new and existing. The Safe System requires a change in focus from mitigating crashes to preventing death and serious injury. Development of the Qatar Road Safety Audit Guide (RSAG) presented an ideal opportunity to reinvigorate road safety auditing practices in accordance with the Safe System. The Public Works Authority (Ashghal) commissioned a RSAG that was to be suitable for Qatar operating environment and based on leading international practices. The Qatar National Road Safety Strategy adopts the Safe System as the model for developing and delivering road safety initiatives, it followed that the RSAG follow the same principles. This was also in accordance with the United Nations: Decade of Action for Road Safety initiative. The RSAG adopts the survivability graph (Wramborg quoted in OECD, 2008) to rank seriousness of deficiencies identified. This allows us to focus on delivering the greatest road safety benefits. Traditional checklists used in road safety audits have been revised to include the possibility of a a head-on crash at 70 km/h, a side-impact crash at 50 km/h, collide with a non-frangible object at 40 km/h or hit a pedestrian at 30 km/h. If the answer is yes to any of these questions there is a need to take action. The Safe System is progressively being implemented globally as a new approach to reducing the unacceptable number of people being killed or injured. The Qatar Road Safety Audit Guide has successfully demonstrated that the Safe System can be integrated into road safety auditing practices.

Road Safety Benefits of High-Risk Corridor Program in British Columbia, Canada

The High-Risk Corridor (HRC) Program of British Columbia, Canada, was created because of recognition that a safe roadway environment is a shared responsibility of several public agencies, including the police and the road authority. In British Columbia, another public agency interested in and responsible for road safety is the Insurance Corporation of British Columbia, a provincial agency responsible for vehicle insurance and driver licensing services. It was felt that coordinated strategic efforts by public agencies responsible for road safety could yield greater safety benefits than individual agency efforts undertaken in isolation. This paper provides an overview of British Columbia’s HRC Program and presents a case study example to demonstrate the program’s success in reducing frequency and severity of collisions on an HRC. The paper also describes the program’s technical elements, including how corridors are defined as high risk and the collision and infrastructure analysis used to guide the interven...