Speed behaviour of car drivers: A statistical analysis of acceptance of changes in speed policies in the Netherlands

Lowering the speed of car drivers will have positive impacts on environmental pollution and the number of road accidents. It is therefore a potentially interesting policy option for governments which want to reduce negative externalities of transport. In this paper, the acceptance of such policies is analysed by means of a survey questionnaire among car drivers and public transport users. First, an analysis is presented on the general speed behaviour, the behaviour on distinct road types, the acceptance of lower limits, and the acceptance and perception of electronic speed limiters. Next, a statistical analysis of subgroups is carried out. It is concluded that the speed of car drivers is, in general, not considered to be a main problematic issue by drivers and non-drivers; therefore, there is little scope for the acceptance of changes in speed policies. When speed policies are changed (lower limits), it seems to be most effective to emphasize safety aspects in order to increase the support of the public. However, psychological factors of speed behaviour may play an important role in this respect.     

Network effects of intelligent speed adaptation systems

Intelligent Speed Adaptation (ISA) systems use in-vehicle electronic devices to enable the speed of vehicles to be regulated automatically. They are increasingly appreciated as a flexible method for speed management and control particularly in urban areas. On-road trials using a small numbers of ISA equipped vehicles have been carried out in Sweden, the Netherlands, Spain and the UK. This paper describes the developments made to enhance a traffic microsimulation model in order to represent ISA implemented across a network and the impact of this on the networks. The simulation modelling of the control system is carried out on a real-world urban network, and the impacts on traffic congestion, speed distribution and the environment assessed. The results show that ISA systems are more effective in less congested traffic conditions. Momentary high speeds in traffic are effectively suppressed, resulting in a reduction in speed variation which is likely to have a beneficial impact on safety. Whilst ISA reduces excessive traffic speeds in the network, it does not affect average journey times. In particular, the total vehicle-hours travelling at speeds below 10 km/hr have not changed, indicating that the speed control had not induced more slow-moving queues to the network. A statistically significant, eight percent, reduction in fuel consumption was found with full ISA penetration. These results are in accordance with those from field trials and they provide the basis for cost-benefit analyses on introducing ISA into the vehicle fleet. However, contrary to earlier findings from the Swedish ISA road trials, this study suggested that ISA is likely to have no significant effect on emission of gaseous pollutants CO, NO_x and HC.     

The pros and cons of Intelligent Speed Adaptation as a restrictive measure for serious speed offenders

In 2011 in the Netherlands a field operational test was performed to investigate the possibility of using restrictive Intelligent Speed Adaptation (ISA) as a penalty system for serious speed offenders. This paper presents the overall results of the research focusing on the pros and cons of the use of ISA as a restrictive measure for serious speed offenders, and on the preconditions for deployment. The results showed that the ISA systems tested have a huge effect on driver behavior and have the potential to improve road safety by reducing the level of speeding, mean speed, as well as the standard deviation of speed. However, there are also cons: the behavioral change in driving behavior was only temporary. In addition the tested technology proved too easy to override, raised issues of equity, and a substantial back office is required when implementing the system for serious speed offenders.     

ITS Solutions and Accident Risks: Prospective and Limitations

Abstract

This article investigates the prospective and limitations in the application of potential intelligent transport system (ITS) functions to reduce accident risks, using a cause‐treatment relationship. The main causes of road accidents are described and appropriate ITS solutions (including advanced driver assistance systems and advanced traveller information systems) are presented as countermeasures. Anticipated impacts are discussed and indicate that several ITS have the potential of improving road safety and addressing specific accident causes. However, attention is required on particular aspects of their implementation as they may trigger adverse effects by imposing behavioural adaptation risks, and overestimation and over‐reliance on system capabilities. Further, user acceptability and strategic implementation issues are paramount to the successful introduction of these systems.     

Spatial impacts of road pricing: Accessibility, regional spillovers and territorial cohesion

Road pricing policies are gaining prominence in EU countries. These policies have positive impacts leading to mobility patterns which are socially and environmentally more desirable, but they also have negative impacts. One negative impact is to be found in regional accessibility, due to the increase in generalized transport costs. This study presents a methodology based on accessibility indicators and GIS to assess the accessibility impacts of a road pricing policy. The methodology was tested for the Spain’s road network considering two road pricing scenarios. It enables not only the more penalized regions to be identified but also negative road pricing spillover effects between regions. These effects are measured in terms of accessibility changes occurring in one region produced by charges implemented in another region. Finally, the study of accessibility disparities (by calculating inequality indexes for each of the scenarios considered), provides policymakers with useful information regarding the impact of road pricing policies from the point of view of territorial cohesion.     

Traffic accident risk perception among drivers: a latent variable approach

ABSTRACT

Governments require decision tools to deal with road traffic accidents, a pandemic resulting in millions of deaths around the world. Evidence shows that human factors are one of the major causes of road accidents, and there is much interest in identifying variables that may have an impact on drivers’ perception of risk. To this aim, we design a stated choice experiment with eight hypothetical driving scenarios considering attributes that have been strongly associated with increased accident risks: (i) driving speed, (ii) driving the wrong way in a one-way street, (iii) overtaking on a bend, and (iv) driving under the influence of alcohol or drugs. Data from a sample of survey respondents are used to estimate a hybrid discrete choice model incorporating two latent variables, Driver Concentration and Safe Driving. Our results may contribute to the design of public policies geared to prevent accidents by encouraging safer driving behaviour.     

Methodological aspects for modeling the environmental risk of transporting hazardous materials by road

The main objective of this paper is to establish the procedures necessary to the development of a model for the environmental risk assessment of accidents involving Transporting Hazardous Materials by Road (THMR). Quantifying the environmental risk is useful in identifying areas with a high risk of accidents, which can be later discarded as main routes; orienting efficient emergency response operations; and assessing policies aimed at reducing these risks. Taking this into consideration, this study endeavors to identify the methodological aspects make possible the assessment of the impacts that arise from accidents involving the transportation of hazardous materials by road and to implement such methodological aspects in a Geographic Information System (GIS).     

Bus accidents,bus deregulation and London

Local bus services were deregulated in October 1986 in all areas of Britain except London. Government policy is to extend deregulation to London, though not in the current parliament. This paper analyses statistics on bus accidents from the national road accident database from 1981 to 1991 to compare results for London and the rest of Great Britain, and to consider whether deregulation has affected safety. The conclusions depend on the assumption that accident recording practice was not itself affected by deregulation.Bus accident rates are higher in London than on built-up roads elsewhere, partly apparently because of road traffic conditions in London, and partly because open-platform buses have higher accident rates involving occupants, including boarding and alighting accidents, than buses with doors.The main safety effects of deregulation operate through its effects on bus activity, though there is also some evidence that the rate per bus-kilometre of accidents involving other road users fell slightly. This may be due in part to the trend towards smaller buses associated with deregulation. Deregulation has led to a fall in bus patronage, and thus to a fall in occupant casualties; and to a rise in bus-kilometres, and thus to a rise in casualties among other road users in accidents involving buses. The number of fatal and serious casualties among other road users involved in bus accidents is larger than the number among bus occupants, so deregulation in London could lead on balance to a small rise in fatalities involving buses. On the other hand, the number of slight casualties among other road users involved in bus accidents is smaller than the number among bus occupants, so deregulation in London could lead to a fall in the number of slight casualties involving buses.Although there were fears that changes in the management of bus operations or financial pressures might lead to increased accident rates following deregulation, there no evidence in the findings to support such fears.This paper was first presented at the 3rd International Conference on Competition and Ownership in Surface Public Transport at Mississauga, Canada on 25–29 September 1993. The author is grateful to the Department of Transport for the speed and efficiency with which they provided special tabulations from the road accident database for this study.     

Investigating effects of asphalt pavement conditions on traffic accidents in Tennessee based on the pavement management system (PMS)

Pavement maintenance is essential for ensuring good riding quality and avoiding traffic congestion, air pollution, and accidents. Improving road safety is one of the most important objectives for pavement management systems. This study utilized the Tennessee Pavement Management System (PMS) and Accident History Database (AHD) to investigate the relationship between accident frequency and pavement distress variables. Focusing on four urban interstates with asphalt pavements, divided median types, and 55 mph speed limits, 21 Negative Binomial Regression models were developed for predicting various types of traffic accident frequencies based on different pavement condition variables, including rut depth (RD), International Roughness Index (IRI), and Present Serviceability Index (PSI). The modeling results indicated that the RD models did not perform well, except for predicting accidents at night and accidents under rain weather conditions; whereas, IRI and PSI were always significant prediction variables in all types of accident models. Comparing the models goodness‐of‐fit results, it was found that the PSI models had a better performance in crash frequency prediction than the RD models and IRI models. This study suggests that the PSI accident prediction models should be considered as a comprehensive approach to integrate the highway safety factors into the pavement management system. Copyright © 2010 John Wiley & Sons, Ltd.     

A Pareto‐improving hybrid policy for transportation networks

This paper investigates an innovative Pareto‐improving hybrid policy that combines two policy instruments, that is, congestion pricing and road space rationing, and takes advantage of the synergistic effects between these instruments. Mathematical formulations for developing Pareto‐improving pure road space rationing schemes and hybrid policies are presented. Numerical examples demonstrate that the proposed hybrid policy offers greater flexibility and is more prominent in leading to Pareto improvement than both pure congestion pricing and road space rationing schemes. Copyright © 2013 John Wiley & Sons, Ltd.     

National policy towards cars: the federal republic of Germany

Although much of the early technical development of the automobile occurred in Germany, the spread of car ownership within Germany was relatively slow up to 1933. Besides the general economic situation, this was due to the high costs of purchasing and running a car. With deliberate promotion of automobility by the national‐socialists after 1933, the pace of motorization proceeded more rapidly until the outbreak of World War II. Immediately after the war, motorization was slow to regain momentum but by the middle fifties, after the initial phase of post‐war reconstruction, the rapid build‐up of cars began again and has continued ever since. By 1986, the West German car fleet exceeded 27 million and 80% of motorized passenger kilometres were made by car.

This rapid post‐war growth was made possible by a liberal transport policy which reacted to growing car use by adaptation and provision of the necessary infrastructure. The adverse effects of vehicular traffic on the environment and on the urban quality of life moved policy at the end of the sixties towards stronger support for urban public transport and regulations for noise and exhaust emissions of automobiles. Also, the high toll of death and injuries from road accidents made improvement of road safety another important policy objective. So far, however, measures taken have fallen short of requiring changes in driver behaviour. Although there is widespread awareness of the environmental and accident costs of automobility, there is a reluctance to legislate (or for people voluntarily) to modify driving behaviour for social objectives.

This paper presents, briefly, the main instruments that have been applied in West Germany to achieve car‐related transport policy objectives, including the latest modifications in the tax system intended to foster the use of low‐emission vehicles. Possible future directions of policy towards the car, depending inter alia on changes in government, are also explored.     

Updating free speed models through mechanistic principles for Indian conditions

The prediction of free speeds of vehicles is an integral part of the economic appraisal of highways. It is to be noted that speeds not only govern the travel time costs, but also have major impacts on Vehicle Operating Costs (VOC). The World Bank has proposed a mechanistic free speed model based on the limiting speed concept for Highway Design and Maintenance (HDM)‐III. This model along with some refinements has been included in HDM‐4. The underlying assumption in the HDM free speed prediction model is that the free speed at any given point of time is the minimum of possible constraining speeds. This paper mainly addresses the methodology considered to update the free speed models through mechanistic principles (based on HDM‐4). This is accomplished by calibration of the model using the current data on free speeds, road and vehicle characteristics. Subsequently, the validation of the developed models has been carried out.     

The safety ladder: developing an evidence-based safety management strategy for small road transport companies

Traffic accidents account for between 20% and 40% of work-related accidents in industrial countries, and research indicates that road transport companies often have little focus on organisational safety management (OSM). There is thus a huge and largely untapped road safety potential in improving the safety of people who drive in their work, by focusing on OSM. Road transport companies in European countries are often small, however, with limited resources in terms of time, financial resources and competence on road safety. The main aim of the present article is therefore to develop an OSM strategy for small road transport companies. Based on a systematic literature review, taking Norwegian research as its point of departure, the article concludes that four measures seem to be most realistic for small goods-transport businesses, and that these measures seem to have the greatest safety potential. These four measures can be arranged on a ladder, where businesses start at the lowest and most basic level, before proceeding to the next step. While our stepwise safety-ladder approach has not been validated, it is expected that further research would confirm the value of the strategy proposed.     

高原地区公路运行速度模型研究

文章基于对青藏公路车辆运行速度、车辆组成的调查,采用层次分析法对不同车辆组成、不同路段速度进行分析,建立了不同车辆组成下的运行速度模型,并结合交通事故数据,提出了确保交通安全的常年冻土区公路运行速度值。该运行速度模型的应用研究,为减少道路交通事故提供了一种新思路。     

Passing Bays for Slow Moving Vehicles on Rural Two‐lane Roads

Abstract

Slow‐moving vehicles, including agricultural vehicles, on arterial highways can cause serious delays to other traffic as well as posing an extra safety risk. This paper elaborates on a small‐scale solution for these problems: the passing bay. It investigates the impacts of a passing bay on the total delay for other motorized vehicles, the number of passing manoeuvres and hindered vehicles, and the mean delay per hindered vehicle. The latter is also considered to be an indicator for traffic safety. The calculations are performed for two characteristic trips with a slow‐moving vehicle. The passing bay is an effective solution to reducing delays on arterial highways when two‐way hourly volumes exceed 600–1000 vehicles. The effects depend on the trip length and speed of the slow‐moving vehicle, and on the passing sight distance limitations of the road. A distance of 2–4?km between the passing bays seems an acceptable compromise between the reduction of delay for other motorized vehicles and the extra discomfort and delay for drivers of slow‐moving vehicles. This result also shows that passing bays are not effective in regions where slow‐moving vehicles mainly make trips shorter than this distance.     

Willingness-to-pay for road safety improvement

Few studies have explored, to date, the issue of the monetary valuation of non-fatal injuries caused by road traffic accidents. The present paper seeks to raise interest in this question and to estimate, by contingent valuation, French households’ willingness-to-pay (WTP) to improve their road safety level and reduce their risk of non-fatal injuries following a road accident. More precisely, a Tobit and a type-II Tobit model were estimated to identify factors for WTP. The results highlighted the significant positive influence of injury severity on WTP. Experience of road traffic accidents seemed to play an important role, positively influencing valuation of non-fatal injury.     

Vehicle insurance and the risk of road traffic accidents

Given the upward trend in incidences of road traffic accidents (RTAs) over recent years, in order to mitigate the financial losses arising from such accidents, governments around the world nowadays generally encourage, or even require, drivers to purchase appropriate vehicle insurance. The primary aim of this study is to examine whether RTAs are directly related to the purchase of vehicle insurance, with our examination of data on vehicle damage insurance policyholders revealing that those drivers who purchase more insurance coverage have a higher probability of being involved in accidents, as a result of which, they will tend to submit more claims. This indicates that insurance coverage might contain information which can be used to assess the probability risk levels of RTAs. We also find that drivers with less safety awareness will tend to purchase more coverage, and that those who purchase more coverage will, in turn, tend to have more accidents and submit more claims. Our findings, which provide a number of road traffic policy implications, would appear to justify the use of the bonus–malus system.     

Historic vehicles: an overview from a transport policy perspective

Historic vehicles (HVs) are the heritage of road transport that have surprisingly received little attention in the academic literature. This study presents an overview of the literature on HVs, focusing on the three topics that dominate the policy debate on transport: environmental, safety and congestion impacts. We observed that polluting emissions of HVs are per kilometre much higher (often a factor 5 or more) than those of moderns vehicles. The annual average mileage per vehicle per year of HVs is much lower than other vehicles. The lower active and passive safety levels of HVs are compensated by the way these vehicles are driven, resulting in the risk factors per kilometre being roughly equal or lower than other vehicles. The contribution of HVs to congestion is negligible. However, the transport policy discourse is divided on the topic of HVs. More comprehensive and effective laws and regulation are needed to protect this aspect of the heritage of road transport whilst concurrently avoiding or limiting the problems caused by them.     

Optimization of tunnel tolls in land use and transport planning

The task of transport planning is to determine cost-effective methods of providing and improving mobility, which can include minimizing traffic congestion. A cost-effective solution to transport problems should consist of a land use pattern, a transport system an a set of road pricing policies that together bring demand and supply into balance in an efficient and equitable way. The conventional approach aimed to produce comprehensive, long-term plans for land use and transport in considerable detail, but tended to ignore the role of road pricing policy, thus ending up with solutions that might not be efficient or economical. This feature of sub-optimal road pricing policy is accentuated by the overall growth in car use, which has generated problems with the efficient use of road space. This paper presents a computer analysis system (or model) which will enable the analysis of coordinated tunnel toll pricing policies by optimising an “objective function” while satisfying the associated and other constraints. The possibility of integrating the optimal road pricing policies in the land use and transport planning are discussed. A case study based on Hong Kong data demonstrates the efficiency of optimizing tolls on two of the three harbour crossing tunnels in Hong Kong.     

Testing a Framework for the Efficiency Assessment of Road Safety Measures

Abstract

The objective of this research is to develop and test a framework for efficiency assessment of road safety measures and evaluate its use in decision‐making. An exhaustive review of standard methodologies and practices related to cost‐effectiveness and cost–benefit analyses is carried out for that purpose. Moreover, a number of case studies are performed, concerning the efficiency assessment of various road safety measures in different countries, covering different types of road safety measures (user‐, vehicle‐ or infrastructure‐oriented, policy or enforcement, etc.), ranging from national to local levels of implementation and including both ex ante and ex post evaluations. From the results conclusions are drawn on the efficiency of different road safety measures and the related determinants. Furthermore, the case studies reveal a number of methodology and data issues for which further research is required. The procedures and barriers involved in the use of efficiency assessment techniques at different levels of decision‐making are also highlighted by means of feedback received during and after the various case studies. On the basis of these results, a framework for the promotion, implementation and evaluation of efficiency assessment in road safety decision‐making is proposed. A particular set of recommendations is also presented regarding the treatment of barriers (fundamental, institutional or technical) within the efficiency assessment itself and the related decision‐making process.