Using biological motion to enhance the conspicuity of roadway workers

This study examined whether the conspicuity of road workers at night can be enhanced by distributing retroreflective strips across the body to present a pattern of biological motion (biomotion). Twenty visually normal drivers (mean age = 40.3 years) participated in an experiment conducted at two open-road work sites (one suburban and one freeway) at night-time. At each site, four road workers walked in place wearing a standard road worker night vest either (a) alone, (b) with additional retroreflective strips on thighs, (c) with additional retroreflective strips on ankles and knees, or (d) with additional retroreflective strips on eight moveable joints (full biomotion). Participants, seated in stationary vehicles at three different distances (80 m, 160 m, 240 m), rated the relative conspicuity of the four road workers. Road worker conspicuity was maximized by the full biomotion configuration at all distances and at both sites. The addition of ankle and knee markings also provided significant benefits relative to the standard vest alone. The effects of clothing configuration were more evident at the freeway site and at shorter distances. Overall, the full biomotion configuration was ranked to be most conspicuous and the vest least conspicuous. These data provide the first evidence that biomotion effectively enhances conspicuity of road workers at open-road work sites.     

Bicyclists overestimate their own night-time conspicuity and underestimate the benefits of retroreflective markers on the moveable joints

Conspicuity limitations make bicycling at night dangerous. This experiment quantified bicyclists’ estimates of the distance at which approaching drivers would first recognize them. Twenty five participants (including 13 bicyclists who rode at least once per week, and 12 who rode once per month or less) cycled in place on a closed-road circuit at night-time and indicated when they were confident that an approaching driver would first recognize that a bicyclist was present. Participants wore black clothing alone or together with a fluorescent bicycling vest, a fluorescent bicycling vest with additional retroreflective tape, or the fluorescent retroreflective vest plus ankle and knee reflectors in a modified ‘biomotion’ configuration. The bicycle had a light mounted on the handlebars which was either static, flashing or off. Participants judged that black clothing made them least visible, retroreflective strips on the legs in addition to a retroreflective vest made them most visible and that adding retroreflective materials to a fluorescent vest provides no conspicuity benefits. Flashing bicycle lights were associated with higher conspicuity than static lights. Additionally, occasional bicyclists judged themselves to be more visible than did frequent bicyclists. Overall, bicyclists overestimated their conspicuity compared to previously collected recognition distances and underestimated the conspicuity benefits of retroreflective markings on their ankles and knees. Participants mistakenly judged that a fluorescent vest that did not include retroreflective material would enhance their night-time conspicuity. These findings suggest that bicyclists have dangerous misconceptions concerning the magnitude of the night-time conspicuity problem and the potential value of conspicuity treatments.     

Seeing pedestrians at night: Visual clutter does not mask biological motion

Although placing reflective markers on pedestrians’ major joints can make pedestrians more conspicuous to drivers at night, it has been suggested that this “biological motion” effect may be reduced when visual clutter is present. We tested whether extraneous points of light affected the ability of 12 younger and 12 older drivers to see pedestrians as they drove on a closed road at night. Pedestrians wore black clothing alone or with retroreflective markings in four different configurations. One pedestrian walked in place and was surrounded by clutter on half of the trials. Another was always surrounded by visual clutter but either walked in place or stood still. Clothing configuration, pedestrian motion, and driver age influenced conspicuity but clutter did not. The results confirm that even in the presence of visual clutter pedestrians wearing biological motion configurations are recognized more often and at greater distances than when they wear a reflective vest.     

Using reflective clothing to enhance the conspicuity of bicyclists at night

Bicycling at night is more dangerous than in the daytime and poor conspicuity is likely to be a contributing factor. The use of reflective markings on a pedestrian's major joints to facilitate the perception of biological motion has been shown to greatly enhance pedestrian conspicuity at night, but few corresponding data exist for bicyclists. Twelve younger and twelve older participants drove around a closed-road circuit at night and indicated when they first recognized a bicyclist who wore black clothing either alone, or together with a reflective bicycling vest, or a vest plus ankle and knee reflectors. The bicyclist pedalled in place on a bicycle that had either a static or flashing light, or no light on the handlebars. Bicyclist clothing significantly affected conspicuity; drivers responded to bicyclists wearing the vest plus ankle and knee reflectors at significantly longer distances than when the bicyclist wore the vest alone or black clothing without a vest. Older drivers responded to bicyclists less often and at shorter distances than younger drivers. The presence of a bicycle light, whether static or flashing, did not enhance the conspicuity of the bicyclist; this may result in bicyclists who use a bicycle light being overconfident of their own conspicuity at night. The implications of our findings are that ankle and knee markings are a simple and very effective approach for enhancing bicyclist conspicuity at night.     

Cyclists’ clothing and reduced risk of injury in crashes

Introduction

A majority of cyclists’ hospital presentations involve relatively minor soft tissue injuries. This study investigated the role of clothing in reducing the risk of cyclists’ injuries in crashes.

Methods

Adult cyclists were recruited and interviewed through hospital emergency departments in the Australian Capital Territory. This paper focuses on 202 who had crashed in transport related areas. Eligible participants were interviewed and their self-reported injuries corroborated with medical records. The association between clothing worn and injury was examined using logistic regression while controlling for potential confounders of injury.

Results

A high proportion of participants were wearing helmets (89%) and full cover footwear (93%). Fewer wore long sleeved tops (43%), long pants (33%), full cover gloves (14%) or conspicuity aids (34%). The primary cause of injury for the majority of participants (76%) was impact with the ground. Increased likelihood of arm injuries (Adj. OR = 2.06, 95%CI: 1.02–4.18, p = 0.05) and leg injuries (Adj. OR = 3.37, 95%CI: 1.42–7.96, p = 0.01) were associated with wearing short rather than long sleeves and pants. Open footwear was associated with increased risk of foot or ankle injuries (Adj. OR = 6.21, 95%CI: 1.58–23.56, p = 0.01) compared to enclosed shoes. Bare hands were associated with increased likelihood of cuts, lacerations or abrasion injuries (Adj. OR = 4.62, 95%CI: 1.23–17.43, p = 0.02) compared to wearing full cover gloves. There were no significant differences by fabric types such as Lycra/synthetic, natural fiber or leather.

Conclusions

Clothing that fully covers a cyclist’s body substantially reduced the risk of injuries in a crash. Coverage of skin was more important than fabric type. Further work is necessary to determine if targeted campaigns can improve cyclists’ clothing choices and whether impact protection can further reduce injury risk.     

Effects of excessive speeding and falling asleep while driving on crash injury severity in Ethiopia: A generalized ordered logit model analysis

The severity of injury from vehicle crash is a result of a complex interaction of factors related to drivers’ behavior, vehicle characteristics, road geometric and environmental conditions. Knowing to what extent each factor contributes to the severity of an injury is very important. The objective of the study was to assess factors that contribute to crash injury severity in Ethiopia. Data was collected from June 2012 to July 2013 on one of the main and busiest highway of Ethiopia, which extends from the capital Addis Ababa to Hawassa. During the study period a total of 819 road crashes was recorded and investigated by trained crash detectors. A generalized ordered logit/partial proportional odds model was used to examine factors that might influence the severity of crash injury. Model estimation result suggested that, alcohol use (Coef. = 0.5565; p-value = 0.017), falling asleep while driving (Coef. = 1.3102; p-value = 0.000), driving at night time in the absence of street light (Coef. = 0.3920; p-value = 0.033), rainfall (Coef. = 0.9164; p-value = 0.000) and being a minibus or vans (Coef. = 0.5065; p-value = 0.013) were found to be increased crash injury severity. On the other hand, speeding was identified to have varying coefficients for different injury levels, its highest effects on sever and fatal crashes. In this study risky driving behaviors (speeding, alcohol use and sleep/fatigue) were a powerful predictor of crash injury severity. Therefore, better driver licensing and road safety awareness campaign complimented with strict police enforcement can play a pivotal role to improve road safety. Further effort needed as well to monitor speed control strategies like; using the radar control and physical speed restraint measures (i.e., rumble strips).     

Influence of front light configuration on the visual conspicuity of motorcycles

A recent study (Cavallo and Pinto, 2012) showed that daytime running lights (DRLs) on cars create “visual noise” that interferes with the lighting of motorcycles and affects their visual conspicuity. In the present experiment, we tested three conspicuity enhancements designed to improve motorcycle detectability in a car-DRL environment: a triangle configuration (a central headlight plus two lights located on the rearview mirrors), a helmet configuration (a light located on the motorcyclist's helmet in addition to the central headlight), and a single central yellow headlight. These three front-light configurations were evaluated in comparison to the standard configuration (a single central white headlight). Photographs representing complex urban traffic scenes were presented briefly (for 250 ms). The results revealed better motorcycle-detection performance for both the yellow headlight and the helmet configuration than for the standard configuration. The findings suggest some avenues for defining a new visual signature for motorcycles in car-DRL environments.     

Revisiting the concept of the ‘problem young driver’ within the context of the ‘young driver problem’: Who are they?

For decades there have been two young driver concepts: the ‘young driver problem’ where the driver cohort represents a key problem for road safety; and the ‘problem young driver’ where a sub-sample of drivers represents the greatest road safety problem. Given difficulties associated with identifying and then modifying the behaviour of the latter group, broad countermeasures such as graduated driver licensing (GDL) have generally been relied upon to address the young driver problem. GDL evaluations reveal general road safety benefits for young drivers, yet they continue to be overrepresented in fatality and injury statistics. Therefore it is timely for researchers to revisit the ‘problem young driver’ concept to assess its potential countermeasure implications. This is particularly relevant within the context of broader countermeasures that have been designed to address the ‘young driver problem’ Personal characteristics, behaviours and attitudes of 378 Queensland novice drivers aged 17–25 years were explored during their pre-, Learner and Provisional 1 (intermediate) licence as part of a larger longitudinal project. Self-reported risky driving was measured by the Behaviour of Young Novice Drivers Scale (BYNDS), and five subscale scores were used to cluster the drivers into three groups (high risk n = 49, medium risk n = 163, low risk n = 166). High risk ‘problem young drivers’ were characterised by greater self-reported pre-Licence driving, unsupervised Learner driving, and speeding, driving errors, risky driving exposure, crash involvement, and offence detection during the Provisional period. Medium risk drivers were also characterised by more risky road use than the low risk group. Interestingly problem young drivers appear to have some insight into their high-risk driving, since they report significantly greater intentions to bend road rules in future driving. The results suggest that tailored intervention efforts may need to target problem young drivers within the context of broad countermeasures such as GDL which address the young driver problem in general. Experiences such as crash-involvement could be used to identify these drivers as a preintervention screening measure.     

Which visual measures affect change in driving difficulty after first eye cataract surgery?

Objective

To investigate self-reported driving difficulty before and after first eye cataract surgery and determine which visual measures are associated with changes in self-reported driving difficulty after surgery.

Methods

A cohort of 99 older drivers with bilateral cataract were assessed the week before and 12 weeks after first eye cataract surgery. Visual measures including visual acuity, contrast sensitivity, stereopsis and useful field of view were assessed. Self-reported driving difficulty was measured via the Driving Habits Questionnaire. Cognitive status was assessed using the Mini Mental State Examination. Regression analysis was undertaken to determine the association between changes in visual measures and self-reported driving difficulty after first eye cataract surgery.

Results

Overall, self-reported driving difficulty improved after first eye cataract surgery. However, 16% of participants did not improve and driving difficulty worsened in 11% following surgery. Improvement in driving difficulty score after first eye cataract surgery was associated with improved contrast sensitivity in the operated eye (p < 0.001), new glasses after surgery (p < 0.001), and fewer chronic health conditions (p = 0.016).

Conclusion

Contrast sensitivity rather than visual acuity was a significant factor affecting change in self-reported driving difficulty after first eye cataract surgery for bilateral patients. This has implications for driver licensing authorities worldwide that rely heavily on visual acuity as a measure of visual fitness to drive.     

Driver behavior during bicycle passing maneuvers in response to a Share the Road sign treatment

The interaction of motorists and bicyclists, particularly during passing maneuvers, is an area of concern to the bicycle safety community as there is a general perception that motor vehicle drivers may not share the road effectively with bicyclists. This is a particular concern on road sections with centerline rumble strips where motorists are prone to crowd bicyclists during passing events. One potential countermeasure to address this concern is the use of a bicycle warning sign with a “Share the Road” plaque. This paper presents the results of a controlled field evaluation of this sign treatment, which involved an examination of driver behavior while overtaking bicyclists. A series of field studies were conducted concurrently on two segments of a high-speed, rural two-lane highway. These segments were similar in terms of roadway geometry, traffic volumes, and other relevant factors, except that one of the segments included centerline rumble strips while the other did not. A before-and-after study design was utilized to examine changes in motor vehicle lateral placement and speed at the time of the passing event as they relate to the presence of centerline rumble strips and the sign treatment. Centerline rumble strips generally shifted vehicles closer to the bicyclists during passing maneuvers, though the magnitude of this effect was marginal. The sign treatment was found to shift motor vehicles away from the rightmost lane positions, though the signs did not significantly affect the mean buffer distance between the bicyclists and passing motorists or the propensity of crowding events during passing. The sign treatment also resulted in a 2.5 miles/h (4.0 km/h) reduction in vehicle speeds. Vehicle type, bicyclist position, and the presence of opposing traffic were also found to affect lateral placement and speed selection during passing maneuvers.     

The effect of a low and high resource intervention on older drivers’ knowledge,behaviors and risky driving

This study aimed to compare an in-class Seniors on the MOVE (Mature Operators Vehicular Education) interactive multi-session driving curriculum with a self-guided MOVE curriculum for older adults. Using a two group randomized design, we sought to determine if there are between-group differences in older drivers’ knowledge and safety behaviors among participants. Forty-four participants with an average age of 79 years (SD = 7.1) were randomly assigned to the original MOVE program (SOM-A) or a lower resource (SOM-B) self-guided intervention. SOM-A is a four session program designed to improve older drivers safety knowledge and better understand skills for safer driving. SOM-B is a self-guided program with one required in-class session and one optional session. Subsequent to completion of both curricula, participants were offered CarFit, a comprehensive check of how well a senior driver and their vehicle work together. Baseline, post-intervention and 6-month follow up questionnaires were completed by participants. We found significant differences (p = .01) in the mean driving safety knowledge scores when comparing participants in SOM-A (3.7, SD 2.0) to those in SOM-B (0.87, SD 2.6). With regard to behavioral outcomes, we focused on always wearing a seatbelt, talking with a health care provider about driving ability, and sitting 10–12 inches from the steering wheel. The vast majority of participants reported always wearing their seat belts (SOM-A 100%, SOM-B 92%, p = 1.0), and very few reported talking with their doctors (SOM-A Baseline – 0%, Follow up 1 – 0%, p = n/a). Mean behavior change scores for participants sitting 10–12 inches from the steering wheel were significantly more likely among SOM-A (mean = .65, SD = .5) participants than those in SOM-B (mean = .29, SD = .5, p = .01) at first follow-up. Taken together, these findings suggest that the more intensive program is more effective and that driving safety programs focused on behaviors to self evaluate driving abilities continue to be needed to help older drivers remain safer on the road as they age. The involvement of health care providers in such efforts may be an untapped potential.     

The distribution of sleepiness,sleep and work hours during a long distance morning trip: A comparison between night- and non-night workers

Few studies have examined the extent of driver sleepiness during a long distance morning trip. Sleepiness at this time may be high because of night work, waking early to commence work or travel, sleep disorders and the monotony of driving long distances. The objective of this study was to estimate the prevalence of chronic sleepiness (Epworth sleepiness score ≥ 10) and sleep restriction (≤5 h) in a sample of 649 drivers. Participants driving between 08:00 and 10:00 on three highways in regional Australia participated in a telephone interview. Approximately 18% of drivers reported chronic sleepiness. The proportions of night workers (NW) and non-night workers (NNW) with chronic sleepiness were not significantly different but males reported a significantly greater proportion of chronic sleepiness than females. The NW group had a significantly greater proportion of drivers with ≤5 h of sleep in the previous 24 and 48 h, fewer nights of full sleep (≤4), acute sleepiness and longer weekly work hours. The NW group reported driving a significantly longer distance at Time 1 (Mean = 140.29 ± 72.17 km, versus 117.55 ± 89.74 km) and an additional longer distance to complete the journey (Mean = 89.33 ± 95.23 km, versus 64.77 ± 94.07 km). The high proportions of sleep restriction and acute sleepiness among the NW group, and the amount of chronic sleepiness in the NW and NNW groups reported during a long distance morning trip may be of concern for driver safety.     

Are car daytime running lights detrimental to motorcycle conspicuity?

For a long time, motorcycles were the only vehicles with daytime running lights (DRLs), but this conspicuity advantage has been questioned due to the rapidly increasing introduction of DRLs on cars as well. The present experiment was designed to assess effects of car DRLs on motorcycle perception in a situation that specifically brought attentional conspicuity to bear. Photographs representing complex urban traffic scenes were displayed briefly (250 ms) to 24 participants who had to detect vulnerable road users (motorcyclists, cyclists, pedestrians) appearing at different locations and distances. Car DRLs hampered motorcycle perception compared to conditions where car lights were not on, especially when the motorcycle was at a greater distance from the observer and when it was located in the central part of the visual scene. Car DRLs also hampered the perception of cyclists and pedestrians. Although the globally positive safety effect of car DRLs is generally acknowledged, our study suggests that more attention should be paid to motorcyclists and other vulnerable road users when introducing car DRLs. Several means of improving motorcycle conspicuity in car DRL environments are discussed.     

Motor vehicle fatalities among oil and gas extraction workers

Motor vehicle crashes are the leading cause of work-related fatality in the U.S. as well as in the oil and gas extraction industry. This study describes the characteristics of motor vehicle-related fatalities in the oil and gas extraction industry using data from the U.S. Bureau of Labor Statistics’ Census of Fatal Occupational Injuries. It compares the risk of dying in a motor vehicle crash in this industry to other major industries and among different types and sizes of oil and gas extraction companies. There were 202 oil and gas extraction workers who died in a work-related motor vehicle crash from 2003 to 2009. The motor vehicle fatality rate for workers in this industry was 8.5 times that of all private wage and salary workers (7.6 vs. 0.9, p < .0001). Workers from small oil and gas establishments (<20 workers) and workers from well-servicing companies were at greatest risk of dying in a motor vehicle crash. Pick-up trucks were the most frequent type of vehicle occupied by the fatally injured worker (n = 104, 51.5%). Safety belt non-use was identified in 38.1% (n = 77) of the cases. Increased focus on motor vehicle safety in this industry is needed, in particular among small establishments. Extraction workers who drive light duty vehicles need to be a specific focus.     

Motorcycle and scooter speeds approaching urban intersections

Five urban, uncontrolled T-intersections known to be motorcycle crash ‘black spots’ were monitored using instrumentation and a roadside observer. Two sets of twelve-hour observations were collected for each site (N ≈ 100,000). Instrumentation recorded the ‘events’ of vehicles passing to measure, speed, direction, lane position, vehicle type (broadly characterised) and headway. Observers further recorded times of bicycle events, type of motorcycle (scooters or motorcycles), the behaviour of motorcycles and the use of ‘high conspicuity’ gear such as clothing or helmets. Results establish that motorcycles travel around 10% faster than the other traffic (car mean speed = 34.97 km/h), with motorcycles travelling on average 3.3 km/h faster than cars. Motorcycles were 3.4 times more likely to be exceeding the speed limit than cars. Similar results are described for scooters. Also examined are the influences on mean speeds such as the time of day, the presence of a car at the t-intersection, and the influence of free headway. The results are compared for robustness across locations and days. It is concluded that in urban areas motorcycles are travelling significantly faster than other traffic. These findings are discussed against a concern to reduce motorcycle crashes by improving conspicuity and previous research that implicates a ‘looked-but-failed-to-see’ effect for car drivers.     

Seatbelt wearing rates in middle income countries: A cross-country analysis

In settings with low seatbelt use prevalence, self-reported seatbelt use estimates often lack validity, and routine observational studies are scarce. In this paper, we aim to describe the prevalence of seatbelt use and associated factors in drivers and front-seat passengers across eight sites in four countries (Egypt, Mexico, Russia, Turkey) using observational studies as well as to produce estimates of country-level and site-level variance. As part of the Bloomberg Philanthropies Global Road Safety Program, data on driver and passenger seatbelt use across four middle-income countries was collected between October 2010 and May 2011 (n = 122,931 vehicles). Logistic regression and Intraclass Correlation Coefficient analyses for sites- and country-level clustering were performed. We found high variability of seatbelt wearing rates ranging from 4 to 72% in drivers and 3–50% in front-seat passengers. Overall, average seatbelt wearing rates were low (under 60% in most sites). At the individual level, older and female drivers were more likely to wear seatbelts, as well as drivers of vehicles transiting at times of increased vehicle flow. We also found that 26–32% and 37–41% of the variance in seatbelt use among drivers and front-seat passengers respectively was explained by differences across sites and countries. Our results demonstrate that there is room for improvement on seatbelt use in middle-income countries and that standardized cross-country studies on road safety risk factors are feasible, providing valuable information for prevention and monitoring activities.     

Older driver distraction: A naturalistic study of behaviour at intersections

This study examined older driver engagement in distracting behaviours (secondary activities) at intersections using naturalistic driving data from a larger study based in Melbourne, Australia. Of interest was whether engagement in secondary activities at intersections was influenced by factors such as driver gender and situational variables, in particular, those relating to the complexity of the driving environment. Specifically we expected that when making left/right turns, older drivers would reduce the proportion of time engaged in secondary behaviours at intersections which required gap judgements (partly controlled or uncontrolled) compared with intersections that were fully controlled by traffic signals. Consideration was given to engagement in secondary activity with hands off the wheel and when the vehicle was moving versus stationary. Older drivers aged between 65 and 83 years drove an instrumented vehicle (IV) on their regular trips for approximately two weeks. The IV was equipped with a video camera system, enabling recording of the road environment and driver and a data acquisition unit, enabling recording of trip distance, vehicle speed, braking, accelerating, steering and indicator use. Driving experience and demographics were collected and functional abilities were assessed using the Useful Field of View (UFOV), Trail Making Test B, Mini Mental Status Examination (MMSE), visual acuity and contrast sensitivity. The study yielded a total of 371 trips with 4493 km (99.8 h) of naturalistic driving data including 1396 left and right turns. Trips were randomly selected from the dataset and in-depth analysis was conducted on 200 intersection manoeuvres (approximately 50% left turns, 50% right turns). The most frequently observed secondary activities were scratching/grooming (42.5%), talking/singing (30.2%) and manipulating the vehicle control panel (12.2%). Glances “off road” 2 s or longer were associated with reading, reaching and manipulation of the vehicle control panel. Hands off the wheel was associated with reading. Key parameters associated with the percent of intersection time that drivers engaged in secondary activities were intersection complexity, vehicle status (moving vs. stationary) and traffic density. In conclusion, older drivers appeared to engage selectively in secondary activities according to roadway/driving situations, supporting the notion that drivers self-regulate by engaging in secondary tasks less frequently when the driving task is more challenging compared with less challenging manoeuvres.     

Traffic violations in Guangdong Province of China: Speeding and drunk driving

The number of speeding- and drunk driving-related injuries in China surged in the years immediately preceding 2004 and then began to decline. However, the percent decrease in the number of speeding and drunk driving incidents (decrease by 22%) is not proportional to the corresponding percent decrease in number of automobile accident-related injuries (decrease by 47%) from the year 2004 to 2010 (Traffic Management Bureau, Ministry of Public Security, Annual Statistical Reports on Road Traffic Accidents). Earlier studies have established traffic violations as one of the major risks threatening road safety. In this study, we examine in greater detail two important types of traffic violation events, speeding and drunk driving, and attempt to identify significant risk factors associated with these types of traffic violations. Risk factors in several different dimensions, including driver, vehicle, road and environmental factors, are considered. We analyze the speeding (N = 11,055) and drunk driving (N = 10,035) data for the period 2006–2010 in Guangdong Province, China. These data, obtained from the Guangdong Provincial Security Department, are extracted from the Traffic Management Sector-Specific Incident Case Data Report and are the only comprehensive and official source of traffic accident data in China. Significant risk factors associating with speeding and drunk driving are identified. We find that several factors are associated with a significantly higher probability of both speeding and drunk driving, particularly male drivers, private vehicles, the lack of street lighting at night and poor visibility. The impact of other specific and unique risk factors for either speeding or drunk driving, such as hukou, road type/grades, commercial vehicles, compulsory third party insurance and vehicle safety status, also require particular attention. Legislative or regulatory measures targeting different vehicle types and/or driver groups with respect to the various driver, vehicle, road and environmental risk factors can subsequently be devised to reduce the speeding and drunk driving rates. As the country with the highest number of traffic accident fatalities in the world, applying these findings in workable legislation and enforcement to reduce speeding and drunk driving rates will save tens of thousands of lives.     

A pattern analysis of traffic crashes fatal to older drivers

A synthesis of the various crash circumstances in which older drivers die is lacking. This study is based on data from Sweden's national archive of fatal RTCs, and focuses on crashes in which the deceased driver was aged 65+ (2002-2004; n = 152). Crash patterns were identified by means of cluster analysis using a sub-set of 12 variables describing both driver and crash event characteristics. Crashes where the driver had died of natural causes prior to crash made up 19.7% of the cases (30 crashes) and were mainly single crashes. Four additional clusters were also identified. Two involved making left turns at intersections, one over-represented among men, occurring typically at weekends, in low-speed areas (30.6%), and the second one, over-represented among women, consisting of crashes in dry road conditions, and on intermediate-speed roads (21.5%). A third cluster included head-on and single-vehicle crashes occurring in dry road conditions but on high-speed roads (29.8%). The last cluster consisted of crashes occurring during the winter and on high-speed roads (18.2%). Older drivers die in traffic in various circumstances, sometimes prior to crashing. Some circumstances cannot be easily alleviated but others could, e.g., through modifications of the road traffic environment and car active safety measures that can help compensate for age-related shortcomings.