Driving speed and the risk of road crashes: A review (original) (raw)

Travelling Speed and the Risk of Crash Involvement: Volume 1: Findings

1997

The relationship between free travelling speed and the risk of involvement in a casualty crash in a 60 km/h speed limit zone was quantified using a case control study design. The 151 case vehicles were passenger cars involved in crashes in the Adelaide metropolitan area which were investigated at the scene by the NHMRC Road Accident Research Unit at Adelaide University and reconstructed using the latest computer aided crash reconstruction techniques. The 604 control vehicles were passenger cars matched to the cases by location, direction of travel, time of day, and day of week and their speeds were measured with a laser speed gun. It was found that the risk of involvement in a casualty crash doubled with each 5 km/h increase in free travelling speed above 60 km/h. Hypothetical speed reductions applied to the case vehicles indicated large potential safety benefits from even small reductions in travelling speed, particularly on arterial roads. (a)

The relationship between travel speeds, infrastructure characteristics, and crashes on two-lane highways

Journal of Transportation Safety & Security, 2017

This paper examined the relationship between travel speeds and crashes on two-lane highways, accounting for traffic exposure and road infrastructure characteristics. The study's database included 179 road sections in Israel, which included free-flow travel speeds, three-year injury crash data, traffic volumes and road infrastructure characteristics. Preliminary analyses of in-data correlations supported the selection of appropriate speed and infrastructure indicators. Homogeneous groups of road sections were identified according to their characteristics. Negative binomial statistical models were fitted to injury crash counts for day-and night-hours, using speed indicators, section length, traffic volume and the homogeneous road groups, which reflected various road design conditions. The models demonstrated a positive relation between mean speeds and crashes, while controlling for traffic and road characteristics. The expected crash change following higher travel speeds was more substantial for night hours. In line with previous research, section length, traffic volume and worse road design were positively related to crashes.

Travelling Speed and the Risk of Crash Involvement on Rural Roads

2001

The relationship between free travelling speed and the risk of involvement in a casualty crash in 80 km/h or greater speed limit zones in rural South Australia was quantified using a case control study design. The crashes involving the 83 case passenger vehicles were investigated at the scene by the Road Accident Research Unit and reconstructed using the latest computer aided crash reconstruction techniques. The 830 control passenger vehicles were matched to the cases by location, direction of travel, time of day, and day of week, and their speeds were measured with a laser speed gun. It was found that the risk of involvement in a casualty crash increased more than exponentially with increasing free travelling speed above the mean traffic speed and that travelling speeds below the mean traffic speed were associated with a lower risk of being involved in a casualty crash. The effect of hypothetical speed reductions on all of the 167 crashes investigated indicated large potential safe...

An Impact of Traffic Characteristics on Crash Frequency

E3S Web of Conferences

With the development of roads, modes of transportation were also developed, and increasing numbers of those modes and routes were needed. This increase brought into focus many problems of the highway system. One of the most important concerns in the highway networks is road safety, which requires various studies to be carried out to reduce crash causalities. One of the factors that affect road safety is the traffic characteristics. This includes average daily traffic, operating speed, traffic density, and heavy vehicles percentage. This study focused on the effect of average daily traffic and heavy vehicles percentage on crash frequency. The old Baghdad – Baquba rural road, a two-lane, two-way road, was chosen for this study. This study used two sets of data (traffic characteristics and crash data). Generalized linear regression models were utilized to develop a model that reflects the effect of the average daily traffic and heavy vehicles percentage on crash frequency. The results ...

Speed, Road Injury, and Public Health

Annual Review of Public Health, 2006

▪ We review milestones in the history of increases in speed limits and travel speeds (“speed creep”) and risks for road deaths and injury. Reduced speed limits, speed-camera networks, and speed calming substantially reduce these tolls in absolute numbers—a trend that is apparent in the United Kingdom, Australia, France, and other countries, but not in the United States, which has raised speed limits and does not have speed-camera networks. Newtonian relationships between the fourth power of small increases or reductions in speed and large increases or reductions in deaths state the case for speed control. Speed adaptation and the interaction between speed and other determinants of injury risks, including congestion and countermeasures, enter into these relationships. Speed-camera networks and speed calming lead to large, sustainable, and highly cost-effective drops in road deaths and injuries and should target entire populations, not merely high-risk subgroups or situations. Yet, ...

Speed limits and accident rates on highways around the world, is there a correlation?

IOP Conference Series: Earth and Environmental Science, Proceedings of the 2nd International Conference on Environmental Design (ICED 2021), 2021

The objective of this study stands for the investigation and evaluation of accidents that take place on highways, in comparison with speed limits. The main body of this research is based on the collection of highways speed limits from different countries around the globe regarding to years, 2010, 2017 and 2018. Secondly, accident rates are collected from highway authorities, as well as from international literature. Subsequently, a statistical analysis of the collected data is conducted and finally leads to an equation that links and correlates the speed limit values and the number of accidents. The results of this statistical analysis show that speed limit plays a certain and distinctive role in the accident rate value. However, one of the interesting findings, stands for the non-continuously increasing number of accidents in the speed limit range, from the lowest to the highest value, meaning that there is an inflection point in the graph of the correlation equation. To be noted, that in terms of this study, the aforementioned correlation is independent of other factors that could affect the accident rate, such as vehicles condition, technology, road network length and condition.

International Journal of Crashworthiness, 2021

Speed is a major risk factor in overall road safety performance. The objective of this study was to identify the most frequent explanatory variables and measures used to investigate the speed factor contribution to crash injury risk (CIR). For this purpose, a literature oriented approach was used. The analysis review, underpinned by data collected from 64 journal publications reported over the past 21 years shows that speed limit was the most frequently used variable selected by the authors to investigate speed contribution CIR. Following, speed delta-V was the second most used variable, despite the barriers to access in-depth crash quality data. Even so, the speed limit was used 3.5 times more than delta-V, possibly due to the facilitate accessibility to the roads standardize posted speed limits. However, it is unknown how much vehicles travel speed could deviate from the posted speed limit at the moment of the crash.

Analysis of effect of speed-limit increases on accident causation and injury severity

2008

The influence of speed limits on roadway safety has been a subject of continuous debate in the State of Indiana and nationwide. In Indiana, highway-related accidents result in about 900 fatalities and forty thousand injuries annually and place an incredible social and economic burden on the state. Still, speed limits posted on highways and other roads are routinely exceeded as individual drivers try to balance safety, mobility (speed), and the risks and penalties associated with law enforcement efforts. The speed-limit/safety issue has been a matter of considerable concern in Indiana since the state raised its speed limits on rural interstates and selected multilane highways on July 1, 2005. In this paper, the influence of the posted speed limit on the severity of vehicle accidents is studied using Indiana accident data from 2004 (the year before speed limits were raised) and 2006 (the year after speed limits were raised on rural interstates and some multi-lane non-interstate routes). Statistical models of the injury severity of different types of accidents on various roadway classes were estimated. The results of the model estimations showed that, for the speed limit ranges currently used, speed limits did not have a statistically significant effect on the severity of accidents on interstate highways. However, for some non-interstate highways, higher speed limits were found to be associated with higher accident severitiessuggesting that future speed limit changes, on non-interstate highways in particular, need to be carefully assessed on a case-by-case basis.

Analysis of the Effect of Speed Limit Increases on Accident-Injury Severities

Driving speed and the risk of road crashes: A review (original) (raw)

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