The effects of mobile roadside speedometers on traffic speeds

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

To speed or not to speed: Thematic analysis of American driving narratives

INTRODUCTION

Speeding is a major cause of unintentional roadway death in the United States. Existing data show that U.S. drivers tend to speed less as they age, but reasons for this change remain largely unknown. Limited research has examined why U.S. drivers decide to speed or why U.S. drivers decide not to speed, and none to date has determined why speeding behaviors change over the life course. Research into these issues can provide insight that may be harnessed for more effective anti-speeding interventions that catalyze decisions not to speed.

METHODS

The current study asked a national sample of U.S. drivers (N = 309) about their driving behaviors and how they have changed over time using an open-ended prompt in an online survey. The authors qualitatively coded responses using a narrative analysis lens to identify common themes.

RESULTS

Results show U.S. drivers often make deliberate choices to speed and some do not consider speeding to be dangerous after achieving perceived mastery of driving skills. Participants tended to report speeding less over time, citing increased concern for family and other roadway users, which may help explain national speeding data trends. Several other themes emerged identifying individual cognitive factors, environmental contexts, and key persons impacting speeding decisions. Practical Applications: Findings show that the most effective means of encouraging U.S. drivers to decide not to speed may be multi-pronged intervention approaches highlighting how speeding reduces roadway driver control, connecting speeding with safety, and encompassing road design and law enforcement strategies.

Driving Safety

Driving is a common and hazardous activity that is a prominent cause of death worldwide. Driver behavior represents a predominant cause, contributing to over 90% of crashes. In this review, I will focus on how driver behavior influences driving safety by describing the types of crashes and their general causes, the driving process, the perceptual and cognitive characteristics of drivers, and driver types and impairments. Evidence from each of these perspectives suggests that breakdowns of a multilevel control process are the fundamental factors that undermine driving safety. Drivers adapt and drive safely in a broad range of situations but fail when expectations are violated or when feedback is inadequate. The review concludes by considering driving safety from a societal risk management perspective.

Effectiveness of a program using a vehicle tracking system, incentives, and disincentives to reduce the speeding behavior of drivers with ADHD

OBJECTIVE

In this article, the authors investigated the effectiveness of a behavior modification program using global positioning system (GPS) vehicle tracking devices with contingency incentives and disincentives to reduce the speeding behavior of drivers with ADHD.

METHOD

Using an AB multiple-baseline design, six participants drove a 5-mile stable driving route weekly while GPS devices recorded speeds. The dependent variable was percentage of feet speeding. Following an initial baseline period, five participants received treatment. One participant remained at baseline.

RESULTS

Visual inspection of individual participant graphs, reductions in mean percentages of speeding from baseline to treatment across participants (M = 82%), C-statistic analyses, and visual graphs with applied binomial formula supported a treatment effect. The between-participant analysis using R n Test of Ranks was significant, R n = 6, p < .01, and complemented a clean multiple-baseline result.

CONCLUSION

Results indicated that this treatment program was effective in reducing speeding by drivers with ADHD and warrants replication.

What benefit does Intelligent Speed Adaptation deliver: a close examination of its effect on vehicle speeds

Intelligent Speed Adaptation (ISA) is a driver support system which brings the speed limit information into the vehicle. This paper describes the UK ISA field trials taken place between 2004 and 2006 and presents evidence on how drivers' choice of speed is altered. The ISA system was observed to have a distinctive effect in transforming the speed distribution from a conventional bell shape to an asymmetric distribution biased towards the high speed end. ISA not only diminished excessive speeding, but also led to a reduction in speed variation, prompting a positive implication to accident reduction. The use of an overridable ISA system also provided an opportunity to investigate where drivers would choose to have ISA based on observed behaviour instead of opinion. Evidence shows that ISA tends to be overridden on roads where it was perhaps needed most. Behavioural difference among driver groups also suggests that ISA tends to be overridden by those drivers who in safety terms stand to benefit most from using it, as with other safety systems.

Speed cameras for the prevention of road traffic injuries and deaths

BACKGROUND

It is estimated that by 2020, road traffic crashes will have moved from ninth to third in the world ranking of burden of disease, as measured in disability adjusted life years. The prevention of road traffic injuries is of global public health importance. Measures aimed at reducing traffic speed are considered essential to preventing road injuries; the use of speed cameras is one such measure.

OBJECTIVES

To assess whether the use of speed cameras reduces the incidence of speeding, road traffic crashes, injuries and deaths.

SEARCH STRATEGY

We searched the following electronic databases covering all available years up to March 2010; the Cochrane Library, MEDLINE (WebSPIRS), EMBASE (WebSPIRS), TRANSPORT, IRRD (International Road Research Documentation), TRANSDOC (European Conference of Ministers of Transport databases), Web of Science (Science and Social Science Citation Index), PsycINFO, CINAHL, EconLit, WHO database, Sociological Abstracts, Dissertation Abstracts, Index to Theses.

SELECTION CRITERIA

Randomised controlled trials, interrupted time series and controlled before-after studies that assessed the impact of speed cameras on speeding, road crashes, crashes causing injury and fatalities were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently screened studies for inclusion, extracted data, assessed methodological quality, reported study authors' outcomes and where possible, calculated standardised results based on the information available in each study. Due to considerable heterogeneity between and within included studies, a meta-analysis was not appropriate.

MAIN RESULTS

Thirty five studies met the inclusion criteria. Compared with controls, the relative reduction in average speed ranged from 1% to 15% and the reduction in proportion of vehicles speeding ranged from 14% to 65%. In the vicinity of camera sites, the pre/post reductions ranged from 8% to 49% for all crashes and 11% to 44% for fatal and serious injury crashes. Compared with controls, the relative improvement in pre/post injury crash proportions ranged from 8% to 50%.

AUTHORS' CONCLUSIONS

Despite the methodological limitations and the variability in degree of signal to noise effect, the consistency of reported reductions in speed and crash outcomes across all studies show that speed cameras are a worthwhile intervention for reducing the number of road traffic injuries and deaths. However, whilst the the evidence base clearly demonstrates a positive direction in the effect, an overall magnitude of this effect is currently not deducible due to heterogeneity and lack of methodological rigour. More studies of a scientifically rigorous and homogenous nature are necessary, to provide the answer to the magnitude of effect.

Speed cameras for the prevention of road traffic injuries and deaths

BACKGROUND

It is estimated that by 2020, road traffic crashes will have moved from ninth to third in the world ranking of burden of disease, as measured in disability adjusted life years. The prevention of road traffic injuries is of global public health importance. Measures aimed at reducing traffic speed are considered essential to preventing road injuries; the use of speed cameras is one such measure.

OBJECTIVES

To assess whether the use of speed cameras reduces the incidence of speeding, road traffic crashes, injuries and deaths.

SEARCH STRATEGY

We searched the following electronic databases covering all available years up to March 2010; the Cochrane Library, MEDLINE (WebSPIRS), EMBASE (WebSPIRS), TRANSPORT, IRRD (International Road Research Documentation), TRANSDOC (European Conference of Ministers of Transport databases), Web of Science (Science and Social Science Citation Index), PsycINFO, CINAHL, EconLit, WHO database, Sociological Abstracts, Dissertation Abstracts, Index to Theses.

SELECTION CRITERIA

Randomised controlled trials, interrupted time series and controlled before-after studies that assessed the impact of speed cameras on speeding, road crashes, crashes causing injury and fatalities were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently screened studies for inclusion, extracted data, assessed methodological quality, reported study authors' outcomes and where possible, calculated standardised results based on the information available in each study. Due to considerable heterogeneity between and within included studies, a meta-analysis was not appropriate.

MAIN RESULTS

Thirty five studies met the inclusion criteria. Compared with controls, the relative reduction in average speed ranged from 1% to 15% and the reduction in proportion of vehicles speeding ranged from 14% to 65%. In the vicinity of camera sites, the pre/post reductions ranged from 8% to 49% for all crashes and 11% to 44% for fatal and serious injury crashes. Compared with controls, the relative improvement in pre/post injury crash proportions ranged from 8% to 50%.

AUTHORS' CONCLUSIONS

Despite the methodological limitations and the variability in degree of signal to noise effect, the consistency of reported reductions in speed and crash outcomes across all studies show that speed cameras are a worthwhile intervention for reducing the number of road traffic injuries and deaths. However, whilst the the evidence base clearly demonstrates a positive direction in the effect, an overall magnitude of this effect is currently not deducible due to heterogeneity and lack of methodological rigour. More studies of a scientifically rigorous and homogenous nature are necessary, to provide the answer to the magnitude of effect.

Aggressive Traffic Enforcement: A Simple and Effective Injury Prevention Program

PURPOSE

To investigate whether an aggressive traffic violation enforcement program could reduce motor vehicle crashes (MVCs), injury collisions, fatalities, and fatalities related to speed, and decrease injury severity in crash victims treated at the trauma center.

METHODS

A vigorous enforcement program was established within Fresno, Calif, city boundaries using increased traffic patrol officers. Data on citations, collisions, fatal collisions, and fatalities related to speed, as well as injury severity from the trauma registry, were collected for the year before program onset (2002), during the first year (2003), and after full implementation (2004). U.S. Census Bureau information was used for population. Statistical analysis was performed using Fisher's exact test and independent samples t test with significance attributed to p < 0.05.

RESULTS

There were significant increases in citations issued, with marked decreases in motor vehicle crashes, injury collisions, fatalities, and fatalities related to speed. There was a decrease in admissions from MVCs, a significant decrease in the number of patients with moderate injury severity (Injury Severity Score of 10-16; p < 0.01), a decrease in hospital length of stay for all MVC victims, and a decrease in hospital charges for MVC patients. These changes were not seen in the area of Fresno County outside the area of increased enforcement.

CONCLUSIONS

Aggressive traffic enforcement decreased MVCs, crash fatalities, and fatalities related to speed, and it decreased injury severity. This is a simple, easily implemented injury prevention program with immediate benefit.

Speed enforcement detection devices for preventing road traffic injuries

BACKGROUND

It is estimated that by 2020, road traffic crashes will have moved from ninth to third in the world ranking of burden of disease, as measured in disability adjusted life years. The identification of effective strategies for the prevention of road traffic injuries is of global public health importance. Measures aimed at reducing traffic speed are considered essential to preventing road injuries; the use of speed enforcement detection devices (including speed cameras and radar and laser devices) is one such measure.

OBJECTIVES

To assess whether the use of speed enforcement detection devices (SEDs) reduces the incidence of speeding, road traffic crashes, injuries and deaths.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, Science (and Social Science) Citation Index, TRANSPORT, PsycINFO, CINAHL, EconLit. We searched the websites of road safety and motoring associations, as well as general internet searches. We handsearched selected journals and conference proceedings, and contacted experts in the field. The searches were conducted during May to November 2004.

SELECTION CRITERIA

Randomised controlled trials and controlled before-after studies that assessed the impact of speed enforcement detection devices on speeding, road crashes, injuries and deaths were eligible for inclusion. For studies involving co-interventions, SEDs had to be the major intervention focus of the study to be eligible.

DATA COLLECTION AND ANALYSIS

We independently screened search results, assessed studies for inclusion, extracted data and assessed methodological quality. Due to variability between and within included studies, a pooled analysis was not appropriate.

MAIN RESULTS

No randomised controlled trials were identified. Twenty-six studies met the inclusion criteria, of which 22 were controlled before-after trials incorporating a distinct control or comparison group(s) and four were interrupted time series designs with a comparison group(s). Fourteen studies reported speed and crash outcomes, seven reported crash outcomes only and five reported speed outcomes only. All but one study reported an absolute reduction in pre/post average speeds. A pre/post reduction in the proportion of speeding vehicles ranged across studies from 5% to 70% depending on the speed threshold set. Pre/post reductions of 50% to 65% were reported in the proportion of speeding vehicles travelling >15 km/h over the speed limit. Compared with controls, the relative improvement was from 1% to 15% for average speed and from 14% to 65% for percent speeding. All studies reporting crash outcomes reported an absolute pre/post reduction in all crashes and injury related crashes. In the vicinity of camera sites these pre/post reductions ranged from 14% to 72% for all crashes, 8% to 46% for injury crashes, and 40% to 45% for crashes resulting in fatalities or serious injuries. More generalised effects over wider areas showed an absolute pre/post crash reduction ranging from 9% to 35%, 7% to 30% for all injury crashes and 13% to 58% for crashes resulting in fatalities alone, or in combination with serious injuries. The studies of longer duration showed that these positive trends were either maintained or improved with time. Compared with controls, the relative improvement in pre/post crash numbers resulting in any type of injury ranged from 5% to 36%.

AUTHORS' CONCLUSIONS

Despite the methodological limitations of the studies reviewed, the consistency of reported positive reductions in speed and crash outcomes across all studies suggest that SEDs are a promising intervention for reducing the number of road traffic injuries and deaths. More studies of a scientifically rigorous nature are necessary to provide a stronger evidence base that these interventions are worthwhile. There is a need for international harmonisation of data collection methods, including standards on how best to measure speeds and collect crash data, over lengthy intervention and follow-up periods, as well as some consensus as to the expression of outcomes in studies, so that studies can be compared.

A conceptual framework for achieving performance enhancing drug compliance in sport

There has been, and continues to be, widespread international concern about athletes' use of banned performance enhancing drugs (PEDs). This concern culminated in the formation of the World Anti-Doping Agency (WADA) in November 1999. To date, the main focus on controlling the use of PEDs has been on testing athletes and the development of tests to detect usage. Although athletes' beliefs and values are known to influence whether or not an athlete will use drugs, little is known about athletes' beliefs and attitudes, and the limited empirical literature shows little use of behavioural science frameworks to guide research methodology, results interpretation, and intervention implications. Mindful of this in preparing its anti-doping strategy for the 2000 Olympics, the Australian Sports Drug Agency (ASDA) in 1997 commissioned a study to assess the extent to which models of attitude-behaviour change in the public health/injury prevention literature had useful implications for compliance campaigns in the sport drug area. A preliminary compliance model was developed from three behavioural science frameworks: social cognition models; threat (or fear) appeals; and instrumental and normative approaches. A subsequent review of the performance enhancing drug literature confirmed that the overall framework was consistent with known empirical data, and therefore had at least face validity if not construct validity. The overall model showed six major inputs to an athlete's attitudes and intentions with respect to performance enhancing drug usage: personality factors, threat appraisal, benefit appraisal, reference group influences, personal morality and legitimacy. The model demonstrated that a comprehensive, fully integrated programme is necessary for maximal effect, and provides anti-doping agencies with a structured framework for strategic planning and implementing interventions. Programmes can be developed in each of the six major areas, with allocation of resources to each area based on needs-assessment research with athletes and other relevant groups.