Driver Age Groups Research Articles

Young Drivers and Crashes Involvements: Frequency and Severity

Young drivers are considering as most risky in driving compared to other age groups of drivers. Understanding the contributing factors affecting traffic crashes caused by young drivers leads to more effective actions for improving road safety. This paper aims to examine the contributing factor affecting the occurrence of young drivers’ crashes. Crash data from 2010 to 2015 has been collected from Abu Dhabi Traffic Police database. At-fault drivers aged between 18 to 24 years is defined as the young drivers in the analysis process. Descriptive statistics show that 23% of severe crashes are caused by young drivers. These crashes resulted 26% of the total fatalities of traffic crashes. Logistic regression model was developed to identify and quantify the variables that affect the occurrence of crashes related to young drivers. The model findings indicated that speeding, sudden lane changing and tailgating are the most caused of young drivers’ crashes. Young drivers are probably to be involved in multi-vehicle crashes and pedestrian-related crashes. Regarding the environmental factors, young drivers have higher risk at night and at intersections compared to older drivers.

An observational study of child safety seat use in an international safe community: Tehran, Iran

ABSTRACTObjective: Despite strong evidence of the effectiveness of child safety seats in reducing injuries, the use of these devices in some communities is still rare. The purpose of this study was to determine the prevalence of child safety seat use and the factors influencing its use in the safe community of Tehran.Methods: This roadside observational study was conducted in 2015 and 2,178 personal cars with a child under 12 years aboard were observed on Tehran's streets in regard to use of child safety seats. Other variables such as the gender of the driver, driver's age group, type of street, region of municipality, time of day, and day of the week were also collected.Results: Prevalence of child safety seat use was 4.3% and was significantly higher among women drivers, on freeways, and in municipal regions 1, 4, and 7.Conclusions: The prevalence of child safety seat use in Tehran as a most populous member of the international safe community was very low and most children commuted in insecure situations in the vehicle. Therefore, it is proposed that plans should be made to increase the use of child safety seats in international safe communities.

Fatality rate of pedestrians and fatal crash involvement rate of drivers in pedestrian crashes: a case study of Iran

The aim of this study was to uncover patterns of pedestrian crashes. In the first stage, 34,178 pedestrian-involved crashes occurred in Iran during a four-year period were grouped into homogeneous clusters using a clustering analysis. Next, some in-cluster and inter-cluster crash patterns were analysed. The clustering analysis yielded six pedestrian crash groups. Car/van/pickup crashes on rural roads as well as heavy vehicle crashes were found to be less frequent but more likely to be fatal compared to other crash clusters. In addition, after controlling for crash frequency in each cluster, it was found that the fatality rate of each pedestrian age group as well as the fatal crash involvement rate of each driver age group varies across the six clusters. Results of present study has some policy implications including, promoting pedestrian safety training sessions for heavy vehicle drivers, imposing limitations over elderly heavy vehicle drivers, reinforcing penalties toward under 19 drivers and motorcyclists. In addition, road safety campaigns in rural areas may be promoted to inform people about the higher fatality rate of pedestrians on rural roads. The crash patterns uncovered in this study might also be useful for prioritizing future pedestrian safety research areas.

Analysis of Rear-End Collisions at Roundabout Approaches

Roundabouts are common alternatives to stop- and signal-controlled intersections and have grown in popularity in response to the promise to reduce traffic crash severity at intersections. In Wisconsin, more than 300 roundabouts have been installed. Studies of these intersections have found a 38% reduction in fatal and injury crashes. However, a 12% overall increase also was found, and this finding is not unique to Wisconsin. An increase in less-serious crashes can lead to a negative public perception about roundabout benefits. The causes of rear-end collisions (a common type of low-severity crash) were examined. Four years of crash reports from 55 roundabouts were analyzed along with the geometric conditions of the roundabouts. The 16- to 24-year-old driver age group represented a significantly higher proportion of involvement in rear-end collisions than in total crashes across the state. Negative binomial models were created for roundabout approaches. For combined one-lane and multilane roundabout approaches, annual average daily traffic, sawtooth pavement markings, and high deflection angles were significantly correlated with an increase in the expected number of rear-end collisions, and wider entry was significantly correlated with a decrease in the expected number of rear-end collisions. For one-lane approaches, “Yield” pavement markings led to an expected reduction in crashes, as did the presence of horizontal curves within 250 feet of a roundabout. These findings reflect the complexity of driving at roundabout approaches, especially for younger drivers. Results also indicate the importance of proper pavement markings at approaches.

Statistical Characteristics of Wrong-Way Driving Crashes on Illinois Freeways

Objective: Driving the wrong way on freeways, namely wrong-way driving (WWD), has been found to be a major concern for more than 6 decades. The purpose of this study was to identify characteristics of this type of crash as well as to rank the locations/interchanges according to their vulnerability to WWD entries.Methods: The WWD crash data on Illinois freeways were statistically analyzed for a 6-year time period (2004 to 2009) from 3 aspects: crash, vehicle, and person. The temporal distributions, geographical distributions, roadway characteristics, and crash locations were analyzed for WWD crashes. The driver demographic information, physical condition, and injury severity were analyzed for wrong-way drivers. The vehicle characteristics, vehicle operation, and collision results were analyzed for WWD vehicles. A method was brought about to identify wrong-way entry points that was then used to develop a relative-importance technique and rank different interchange types in terms of potential WWD incidents.Results: The findings revealed that a large proportion of WWD crashes occurred during the weekend from midnight to 5 a.m. Approximately 80% of WWD crashes were located in urban areas and nearly 70% of wrong-way vehicles were passenger cars. Approximately 58% of wrong-way drivers were driving under the influence (DUI). Of those, nearly 50% were confirmed to be impaired by alcohol, about 4% were impaired by drugs, and more than 3% had been drinking. The analysis of interchange ranking found that compressed diamond interchanges, single point diamond interchanges (SPDIs), partial cloverleaf interchanges, and freeway feeders had the highest wrong-way crash rates (wrong-way crashes per 100 interchanges per year).Conclusions: The findings of this study call for more attention to WWD crashes from different aspects such as driver age group, time of day, day of week, and DUI drivers. Based on the analysis results of WWD distance, the study explained why a 5-mile radius of WWD crash location should be studied for WWD fatal crashes with unknown entry points.

The impact and sustainability of the graduated driver licensing program in preventing motor vehicle crashes in Massachusetts.

Graduated driving licensing (GDL) programs phase in driving privileges for teenagers. We aimed to evaluate the effect of the 2007 GDL law on the incidence of total motor vehicle crashes (tMVCs) and fatal motor vehicle crashes (fMVCs) among teenagers in Massachusetts. The Fatality Analysis and Reporting System, the Missouri Census Data Center, and the Massachusetts Department of Transportation databases were all used to create and compare the incidence of tMVCs and fMVCs before (2002-2006) and after (2007-2011) the law enactment. The following three driver age groups were studied: 16 years to 17 years (evaluating the law effect), 18 years to 20 years (evaluating the sustainability of the effect), and 25 years to 29 years (control group). As a sensitivity analysis, we compared the incidence rates per population and per licenses issued. tMVCs decreased following the law for all three age groups (16-17 years, from 7.6 to 4.8 per 1,000 people, p < 0.0001; 18-20 years, from 8.5 to 6.4 per 1,000 people, p < 0.0001; 25-29 years, from 6.2 to 5.2 per 1,000 people, p < 0.0001), but the percentage decrease in tMVC rates was less in the control group (37%, 25%, and 15%, respectively; both p's < 0.0001). The rates of fMVC also decreased in the age groups of 16 years to 17 years (from 14.0 to 8.6 per 100,000 people, p = 0.0006), 18 years to 20 years (from 21.2 to 13.7 per 100,000 people, p < 0.0001), and 25 years to 29 years (from 14.4 to 11.0 per 100,000 people, p < 0.0001). All of these results were confirmed in the sensitivity analyses. The 2007 Massachusetts GDL was associated with a decreased incidence of teenager tMVCs and fMVCs, and the effect was sustainable. This study provides further support to develop, implement, enforce, and maintain GDL programs aimed at preventing MVCs and their related mortality in the young novice driver population. Epidemiologic/prognostic study, level III.

The Impact of Michigan's Text Messaging Restriction on Motor Vehicle Crashes

PurposeThe purpose of this study was to determine the effects of Michigan's universal text messaging restriction (effective July 2010) across different age groups of drivers and crash severities. MethodsChanges in monthly crash rates and crash trends per 10,000 licensed drivers aged 16, 17, 18, 19, 20–24, and 25–50 years were estimated using time series analysis for three levels of crash severity: (1) fatal/disabling injury; (2) nondisabling injury; and (3) possible injury/property damage only (PDO) crashes for the period 2005–2012. Analyses were adjusted for crash rates of drivers' aged 65–99 years, Michigan's unemployment rate, and gasoline prices. ResultsAfter the introduction of the texting restriction, significant increases were observed in crash rates and monthly trends in fatal/disabling injury crashes and nondisabling injury crashes, and significant decreases in possible injury/PDO crashes. The magnitude of the effects where significant changes were observed was small. ConclusionsThe introduction of the texting restriction was not associated with a reduction in crash rates or trends in severe crash types. On the contrary, small increases in the most severe crash types (fatal/disabling and nondisabling injury) and small decreases in the least severe crash types (possible injury/PDO) were observed. These findings extend the literature on the effects of cell phone restrictions by examining the effects of the restriction on newly licensed adolescent drivers and adult drivers separately by crash severity.

The culpability of drivers killed in New Zealand road crashes and their use of alcohol and other drugs

Over a period of five years, blood samples were taken from 1046 drivers killed as a result of a motor vehicle crash on New Zealand roads. These were analysed for the presence of alcohol and a range of both illicit drugs and psychoactive medicinal drugs. Driver culpability was determined for all crashes. The control group of drug- and alcohol-free drivers comprised 52.2% of the study population. Drivers positive for psychoactive drugs were more likely to be culpable (odds ratio (OR) 3.5, confidence interval (CI) 95% 2.4–5.2) than the control group. Driver culpability exhibited the expected positive association with alcohol use (OR 13.7, 95% CI 4.3–44) and with combined alcohol and cannabis use (OR 6.9, 95% CI 3.0–16). There was only a weak positive association between cannabis use (with no other drug) and culpability (OR 1.3, CI 95% 0.8–2.3). Furthermore, the OR for drivers with blood tetrahydrocannabinol (THC) concentrations greater than 5ng/mL was lower (OR 1.0, CI 95% 0.4–2.4) than drivers with blood THC concentrations less than 2ng/mL (OR 3.1, CI 95% 0.9–10). This is inconsistent with results reported by other studies where a significant increase in crash risk was found with blood THC levels greater than 5ng/mL. In this study, there were very few drivers who had used a single drug, other than cannabis or alcohol. Therefore, from this study, it is not possible to comment on any relationship between opioid, stimulant or sedative drug use and an increased risk of being killed in a crash for the drivers using these drugs. The results from a multivariate analysis indicate that driver gender, age group and licence status, (P=0.022, P=0.016, P=0.026, respectively), the type of vehicle being driven (P=0.013), the number of vehicles in the crash (P<0.001), the blood alcohol concentration of the driver (P<0.001) and the use of any drug other than alcohol and cannabis (P=0.044), are all independently associated with culpability.

Predictors of intrinsic motivation behind seatbelt use in a country where current use is low

ContextSeatbelt use is a major determinant of a driver's safety on the road. In Turkey and other middle-income countries, seatbelt use is lower than in high-income countries and contributes to the higher burden of road traffic injuries. Assessing factors behind drivers' motivations to wear seatbelts can help determine appropriate interventions for specific subpopulations. ObjectiveTo analyze the factors predictive of whether drivers who wear seatbelts in Afyonkarahisar and Ankara, Turkey do so because they believe seatbelts can save their lives. MethodsAs part of the monitoring and evaluation of the Bloomberg Philanthropies Global Road Safety Programme, 817 drivers were randomly recruited in Afyonkarahisar and Ankara, Turkey, to participate in roadside interviews. Logistic regression was run on data from 408 drivers who claimed they always wore seatbelts. Predictors were driver's city, driver's age group (30 and younger, 31 to 40, and over 40 years), whether at least one passenger was in the car, and an interaction term between age group and whether passengers were in the car. The outcome variable of interest was whether drivers wore seatbelts because they believed seatbelts can save their lives, referred to in this paper as “selection of Reason 3.” ResultsThe odds of selecting Reason 3 were 2.45 (95% CI: 1.40–4.31) times higher in Ankara than in Afyonkarahisar, 2.52 (95% CI: 1.38–4.60) and 3.65 (95% CI: 1.92–6.95) times higher for drivers aged 31–40 and drivers over the age of 40 than for drivers 30 years of age and younger, respectively, and 5.89 (95% CI: 2.02–17.23), 7.22 (95% CI: 1.61–32.42), and 0.83 (95% CI: 0.32–2.19) times higher for drivers traveling with passengers who were 30 years of age and younger, between 31 and 40, and over 40 than for drivers traveling without passengers in these age groups, respectively. ConclusionDrivers with passengers had higher odds of selecting Reason 3, especially younger drivers who are more likely to succumb to peer pressure. Older drivers had higher odds of selecting Reason 3. Peer groups and peer education campaigns may have an impact. Education interventions combined with extrinsic campaigns can be aimed at younger drivers to increase and maintain adherence in the population.

Application of the theory of planned behaviour to predict young drivers' speeding behaviour

BackgroundSpeeding involvement has been reported to be as high as nearly 80% of all traffic crashes on national highways in Thailand. It was found that young drivers tend to drive...

An Evaluation of Graduated Driver Licensing Effects on Fatal Crash Involvements of Young Drivers in the United States

Objective: Graduated driver licensing (GDL) systems are designed to reduce the high crash risk of young novice drivers. Almost all states in the United States have some form of a 3-phase GDL system with various restrictions in the intermediate phase. Studies of the effects of GDL in various states show significant reductions in fatal crash involvements of 16- and 17-year-old drivers; however, only a few national studies of GDL effects have been published. The objective of this national panel study was to evaluate the effect of GDL laws on the fatal crash involvements of novice drivers while controlling for possible confounding factors not accounted for in prior studies. Methods: The Fatality Analysis Reporting System (FARS) was used to examine 16- and 17-year-old driver involvement in fatal crashes (where GDL laws are applied) relative to 2 young driver age groups (19–20, 21–25) where GDL would not be expected to have an effect. Dates when various GDL laws were adopted in the states between 1990 and 2007 were coded from a variety of sources. Covariates in the longitudinal panel regression analyses conducted included 4 laws that could have an effect on 16- and 17-year-old drivers: primary enforcement seat belt laws, zero-tolerance (ZT) alcohol laws for drivers younger than age 21, lowering the blood alcohol concentration limit for driving to 0.08, and so-called use and lose laws where drivers aged 20 and younger lose their licenses for underage drinking violations. Results: The adoption of a GDL law of average strength was associated with a significant decrease in fatal crash involvements of 16- and 17-year-old drivers relative to fatal crash involvements of one of the 2 comparison groups. GDL laws rated as “good” showed stronger relationships to fatal crash reductions, and laws rated as “less than good” showed no reductions in crash involvements relative to the older driver comparison groups. Conclusions: States that adopt a basic GDL law can expect a decrease of 8 to 14 percent in the proportion of 16- and 17-year-old drivers involved in fatal crashes (relative to 21- to 25-year-old drivers), depending upon their other existing laws that affect novice drivers, such as those used in these analyses. This finding is consistent with recent national studies that used different outcome measures and covariates. The results of this study provide additional support for states to adopt, maintain, and upgrade GDL systems to reduce youthful traffic crash fatalities.

Comparison of two methods to assess the effect of age and sex on the risk of car crashes

Background This study was designed to compare two methods (direct measurement of exposure and quasi-induced exposure) for assessing the effect of age and sex on the risk of being involved in a car crash in Spain. Methods Spanish crash rates (per 10,000,000 driver-km) for age and sex groups of drivers aged 18–64 years old were obtained for 2004–2007, using information from the Spanish General Traffic Office (census of reported car crashes) and the Spanish Household Survey on Alcohol and Drugs (estimate of the mean km driven for each car driver). The rate ratios estimated by direct exposure estimates were compared to those obtained with the quasi-induced exposure method, which compares the age and sex of responsible and non-responsible drivers involved in the same clean collision (in which only one of the drivers committed a driving infraction). Results Both methods detected an increased risk of involvement in a crash for the youngest (18–20 years) and the oldest drivers (60–64 years), compared to middle-aged drivers (45–49 years). However, the rate ratios obtained with the quasi-induced method for the youngest group (2.0 for men, 1.6 for women) were much lower than those obtained with crash rates (13.4 for men, 5.7 for women). Both methods detected a similar increase in the risk of involvement of male drivers compared to women in the youngest age group. This excess risk for men was maintained with increasing age up to 45–49 years when the quasi-induced method was used. However, direct comparisons of crash rates revealed an increased risk of involvement in women compared to men of the same age from 25–29 years onward. Conclusions Both direct measurement of driving exposure and the quasi-induced exposure method detected some well-known patterns of risk associated with driver's age and sex. However, factors that could explain important differences between the two methods deserve attention, especially those related with the excess risk for the youngest drivers as well as sex-related risk.

Effects of Driver Age and Dimensions of the Stop Sign on Braking Distance Performance at Stop-Controlled Intersections

Guidelines for the use of traffic control devices at stop-controlled intersections in the United States are provided in the Manual on Uniform Traffic Control Devices (MUTCD). Based on that, different dimensions of stop signs could be employed, even within the same jurisdiction. The study summarized in this paper investigated the effects of driver age and dimensions of stop signs on braking distance performance at stop-controlled intersections, while paying particular attention to older drivers. Data were collected at several stop-controlled intersections in non-residential areas in Hillsborough County, Florida, where three different sizes of stop signs (30", 36", and 48") were in use. Three driver age groups were also considered: older drivers, middle-age drivers, and young drivers. Statistical testing was used to find out whether the braking distances were different among driver age groups and also among different sizes of stop signs. Based on the observational data, it was found that older drivers had significantly longer braking distances for the largest size of the stop sign. Braking distances were also significantly different among the driver groups for the two larger sizes of the stop signs, but not for the smallest. In other words, older drivers see the larger sign and apply the brakes sooner resulting in longer braking distances. As such, the study recommends considering the replacement of smaller sizes of stop signs with the largest size in non-residential areas with a high older-driver population to increase safety at stop-controlled intersections.

Age group differences in collision risk

Introduction The purpose of the current study was to examine differences in factors associated with self-reported collision involvement of three age groups of drivers based on a large representative sample of Ontario adults. Method: This study was based on data from the CAMH Monitor, an ongoing cross-sectional telephone survey of Ontario adults 18 years and older from 2002 to 2005. Three age groups were examined: 18-34 (n = 1,294), 35-54 (n = 2,428), and 55+ (n = 1,576). For each age group sample, a logistic regression analysis was conducted of self-reported collision involvement in the last 12 months by risk factor measures of driving exposure (kilometers driven in a typical week, driving is stressful, and driving on busy roads), consuming five or more drinks of alcohol on one occasion (past 12 months), cannabis use (lifetime, and past 12 months), and driving after drinking among drinkers (past 12 months), controlling for demographics (gender, region, income, and marital status). Results: The study identified differences in factors associated with self-reported collision involvement of the three age groups of adult drivers. The logistic regression model for the youngest group revealed that drivers who reported that driving was stressful at least some of the time, drank five or more drinks on an occasion, and drove after drinking had an increased risk of collision involvement. For the middle age group, those who reported using cannabis in the last 12 months had significantly increased odds of reporting collision involvement. None of the risk factor measures showed significant associations with collision risk for older drivers (aged 55+). Impact: The results suggest potential areas for intervention and new directions for future research.

Measuring Drivers' Frustration in a Driving Simulator

The objective of the current study was to measure the effect of frustration on drivers' performance and scanning efficiency in a driving simulator. We hypothesized that unsafe driving would be elicited by a combination of manipulating frustrating events in the external driving environment while inducing a sense of time pressure within the driver. Two age groups of drivers drove through several frustrating situations on the road while trying to reach a destination within a limited time. The induced frustration decreased drivers' awareness of potential distractions, mental state, and potential danger in driving environment. When compared to younger drivers, older drivers had a more efficient scanning routine and safer vehicle control. This study speaks to the need for emotionally engaging simulated driving scenarios to produce more realistic driver performance.

Role of Poverty in California Teenagers’ Fatal Traffic Crash Risk

Teenagers’ high rates of motor vehicle crashes, accounting for 40% of external deaths among 16-19 yearolds, have been ascribed largely to inherent “adolescent risk-taking” and developmental hazards. However, the fact that compared to adults 25 and older, teenagers are twice as likely to live in poverty and low-income areas, risk factors for many types of violent death, has not been assessed. This paper uses Fatality Analysis Reporting System data on 65,173 fatal motor vehicle crashes by drivers in California’s 35 most populous counties for 1994-2007 to analyze fatal crash involvements per 100 million miles driven by driver age, county, poverty status, and 15 other traffic safety-related variables. Fatal crash rates were substantially higher for every driver age group in poorer counties than in richer ones. Multivariate regression found socioeconomic factors, led by the low levels of licensing and high unemployment rates prevalent in low-income areas, were associated with nearly 60% of the variance in motor vehicle crash risks, compared to 3% associated with driver age. The strong association between fatal crash risk and poverty, especially for young drivers who are concentrated in high-poverty brackets and low-income areas, suggests that factors related to poorer environments constitute a major traffic safety risk requiring serious attention.

Reliability of drivers in urban intersections

The concept of human reliability has been widely used in industrial settings by human factors experts to optimise the person-task fit. Reliability is estimated by the probability that a task will successfully be completed by personnel in a given stage of system operation. Human Reliability Analysis (HRA) is a technique used to calculate human error probabilities as the ratio of errors committed to the number of opportunities for that error. To transfer this notion to the measurement of car driver reliability the following components are necessary: a taxonomy of driving tasks, a definition of correct behaviour in each of these tasks, a list of errors as deviations from the correct actions and an adequate observation method to register errors and opportunities for these errors. Use of the SAFE-task analysis procedure recently made it possible to derive driver errors directly from the normative analysis of behavioural requirements. Driver reliability estimates could be used to compare groups of tasks (e.g. different types of intersections with their respective regulations) as well as groups of drivers’ or individual drivers’ aptitudes. This approach was tested in a field study with 62 drivers of different age groups. The subjects drove an instrumented car and had to complete an urban test route, the main features of which were 18 intersections representing six different driving tasks. The subjects were accompanied by two trained observers who recorded driver errors using standardized observation sheets. Results indicate that error indices often vary between both the age group of drivers and the type of driving task. The highest error indices occurred in the non-signalised intersection tasks and the roundabout, which exactly equals the corresponding ratings of task complexity from the SAFE analysis. A comparison of age groups clearly shows the disadvantage of older drivers, whose error indices in nearly all tasks are significantly higher than those of the other groups. The vast majority of these errors could be explained by high task load in the intersections, as they represent difficult tasks. The discussion shows how reliability estimates can be used in a constructive way to propose changes in car design, intersection layout and regulation as well as driver training.

Disaggregate Propensity Study on Red Light Running Crashes Using Quasi-Induced Exposure Method

Red light running (RLR) is a serious traffic hazard at signalized intersections. A number of studies have been undertaken to understand the characteristics and prevalence of highway users involved in RLR crashes. However, most of the studies did not consider crash exposure systematically. To overcome the difficulties in obtaining direct exposure information, this study made use of the quasi-induced exposure method to identify the significant driver-vehicle characteristics that influence RLR crash propensity. This was done by developing models of relative exposure for intersections and relative crash involvement ratio for RLR crashes. Using crash data in Singapore from 1993 to 2002, a disaggregate analysis identified a number of significant factors contributing to RLR crash propensity for different driver age and gender groups, and vehicle types under various road environments. The results show that the problem related to RLR crashes is not just related to driver or vehicle or the road environment but a combination of these factors. Arising from the results of this study, potential countermeasures in reducing the high RLR crash risk for specific highway user cohorts are discussed and recommended.

Do Older Drivers Pose a Risk to Other Road Users?

Objective: To investigate the extent to which older drivers pose a risk to other road users, relative to drivers of other ages, using Australian fatal crash data. Method: The principal data source was the Australian Transport Safety Bureau's National Fatalities Database, which has provided fatality numbers for the most recent available 10-year period (1988, 1990, 1992, 1994, and 1996–2001). For each driver age group (“target drivers”), fatality rates were calculated for the following categories of road users: target driver deaths, their passenger deaths, road users external to the target vehicle but killed in the crash involving the target driver, all road users killed other than target drivers, and all road users killed (including target drivers). Fatality rates were calculated on three bases: per population numbers in each age category, per licensed driver numbers in each age category, and per distance driven for each age category. The different road user fatality rates associated with drivers aged 80 years and older were compared to the rates associated with drivers from younger age categories. Results: On a per population basis, older drivers had a significantly lower “all road users” fatality rate than all age groups bar one (RR for other age groups: 1.2–3.1) and these differences strengthened once target drivers were excluded (RR: 1.4–5.1), all differences significant. On a per licence basis, older drivers had significantly higher “all road users” fatality rate when compared to the rates for drivers aged 30–39 years through to 70–79 years (RR for these age groups: 0.5–0.7) but once the target drivers were excluded, older drivers' “all other road users & fatality rates for were significantly lower than for drivers aged 17–24 years to 30–39 (RR: 1.3–2.6) years. On a per-distance basis, older drivers had significantly higher all road users fatality rate when compared to the rates for all drivers aged 25–29 years through to 70–79 years (RR for these age groups: 0.1–0.4). Once the target drivers were excluded, older drivers' all other road users fatality rates remained significantly higher than for these other age groups (RR: 0.3–0.7) years. Conclusions: Based on two of the three bases (per population and per licence), it has been strongly asserted that overall, the older the driver, the less the threat to other road users—and particularly, the less the threat to road users external to the driver's vehicle. Drivers aged 80 years and older appeared to be the greatest threat to other road users only when per distance fatality rates were compared.

Modeling Driver Behavior within a Signalized Intersection Approach Decision–Dilemma Zone

This study uses data gathered in a field test on 60 test participants to develop models that characterize driver brake perception–reaction times (PRTs), brake times, and stop–go decisions at the onset of a yellow indication at a high-speed signalized intersection approach. The study demonstrates that driver PRTs are influenced only by the driver's time to intersection (TTI) at the onset of the yellow indication. The driver PRT is found to increase linearly with TTI and is not affected by the vehicle speed (in the range of 54 to 88 km/h), driver gender, or driver age. In the case of stop–go behavior, the older driver (≥65 years of age) dilemma zone is wider, ranging from a TTI of 4.81 to 1.66 s versus 4.90 to 2.87 s for the younger age group. Female drivers are more likely to stop than male drivers and tend to have a dilemma zone that is closer to the intersection. Finally, the study demonstrates that dilemma zone control systems should consider a dilemma zone from 5.0 to 1.5 s instead of the current state of practice of 5.5 to 2.5 s to capture all potential driver age and gender groups.