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Abstract
Objective—To assess injury prevention measures used by cyclists in Oxford and to detect any differences between wearers and non-wearers of cycling helmets.
Method—A prospective observational survey of a series of cyclists passing a single point on a busy city road in reduced lighting. Two observers jointly recorded four measures of injury prevention: use of front or rear light, high visibility (reflective or fluorescent) clothing, and cycling helmet. The use of the first three interventions was analysed in relation to helmet use/non-use.
Results—A total of 392 cyclists were observed over one hour. Fourteen (3.6%) were observed to use all four studied measures, while 137 (34.9%) used none of them. The frequency of measures observed was: lit front light 190 (48.5%), lit rear light 197 (50.2%), both lights on 163 (41.6%), helmet on 104 (26.5%), and high visibility clothing 39 (9.9%).
Despite the helmet using group's smaller size, it contained a significantly higher proportion of cyclists with lit front light (60.6% v 44.1%), lit rear light (61.5% v 46.2%), and high visibility clothing (27.9% v 3.5%), than the non-helmet group (p≤0.01). Whereas only 22% of the helmet users had no other observed measures, 47.2% of non-users did so.
Conclusion—Cycling helmet users were significantly more likely to use collision prevention measures in conditions of reduced visibility. Explanations may include higher levels of risk awareness and greater knowledge of safe cycling practices in the smaller, helmet using group. However, current measures by cyclists in a major cycling centre may be insufficient to prevent collisions and consequent serious injury or death.
- cycling
- protective clothing
- cycle lights
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Oxford has been termed the unofficial cycling capital of the UK. Thriving tourism and Britain's oldest university contribute to the motor traffic that regularly congests the city centre. Local planning countermeasures promote already widespread bicycle use, which increases exposure of cyclists to motor traffic, and hence increases potential for injury.
Although most adult cycling accidents do not involve motor vehicles,1,2 such high velocity impacts cause the majority of deaths.3,4 Adult cyclists struck by motor vehicles are more likely to be struck at night, less likely to be responsible for the event, and more likely to suffer serious injury or death.5,6 Common scenarios are when a vehicle is turning across traffic, striking an oncoming cyclist, or overtaking a cyclist travelling in the same direction.7
The first advanced stopline in the UK was introduced in Oxford. These are now widely used road markings, which create a safe zone for cyclists ahead of motor vehicles at traffic lights. Subsequent traffic separation strategies have included cycle lanes on many main roads, and three extensive off-road cycle paths.
A number of publications are issued to educate cyclists about safety in the area, while Thames Valley Police run occasional two week campaigns publicising the legal requirement for functioning rear and front lights after dusk.8 In the first week, cyclists failing to comply are stopped and cautioned; in the second week, offending cyclists may be stopped and offered a choice of prosecution or fine. In 1997 during such a campaign, 800 adult cyclists were cautioned in two weeks, while 200 were issued tickets (Thames Valley Police, personal communication). Although no campaign was in practice at the time of this study, a commonly used monitoring point is located 400 m along the road studied.
Strategies to reduce damage and injuries may be developed by studying interactions between factors (human, vehicular, and environmental) in three phases (pre-event, event, and post-event) of accidents.9 In the event phase of cyclist collisions, safety helmets reduce the risk of significant head injury and death.3 Pre-event environmental strategies include separation of cyclists from other traffic, while pre-event human factors may be improved with adequate standards of education and testing of proper road use. Cycling lights and high visibility (reflective or fluorescent) clothing are classed as pre-event equipment factors. The use of such equipment, which may reduce risk of collision in conditions of reduced visibility, has not been previously studied in the UK.
Methods
A single observation point was identified on a busy, central two way road serving both university and business areas in the city, with four bus stops within 100 m on each side of the road, and no cycling lane. This would provide a random sample of the whole cycling population of the city. Consecutive cyclists passing only outward from the city centre were observed to prevent those returning within the study period being recorded twice.
The study was carried out at dusk during the latter part of the evening rush period, from 17:30 (when most motor vehicles had lights on) until 18:30 (when no daylight remained). Street lighting time was at 18:00. Cyclist visibility was therefore reduced throughout the period of study.
Cyclists were observed for three collision prevention measures—high visibility clothing, and active use of front and rear cycle lights—and one injury prevention measure, the use of a cycle helmet. Observations were made simultaneously by two investigators. It was agreed that cases of disagreement would represent insufficiently visible measures, and as such would be recorded as negatives.
The use of the three collision prevention interventions was compared in the helmet wearing and non-helmet wearing groups.
Results
A total of 392 cyclists passed the observation point within the study period. Observations of the four recorded safety measures are shown in table 1.
Frequency of interventions in helmet users v helmet non-users
The most common measure observed was a rear light, with 163 (82.7%) of these also using a lit front lamp. In some cyclists, a lit cycle lamp was the sole intervention: 18 (4.6%) front or 23 (5.9%) rear. High visibility clothing was noted in 39 (9.9%) cyclists; it was seen far more commonly in conjunction with a helmet, and never as a sole safety measure. None of the measures being observed were present in 137 cyclists (34.9%).
During the study, an incidental impression was that cyclists wearing helmets used the other observed safety measures more frequently than those who did not. Comparing the two groups (table 1) confirmed significant differences in the use of all observed safety measures (p≤0.01), with higher proportions of all measures in the helmet using group.
Discussion
One third of all cyclists observed used none of the four preventative measures while exposed to heavy motor traffic in reduced lighting conditions. Altogether 288 (73.5%) wore no helmet, in keeping with results of previous local studies. Cyclists with helmets were more likely however, to use other safety measures. In contrast, those without helmets were more likely to use none of the other measures.
The presence of four busy bus stops adjacent to our observation point caused frequent stopping and starting of traffic, with consequent regular overtaking. This further exposed cyclists to oncoming vehicles. Consequently, this environment had a number of factors predisposing to cyclist/motor collisions, and might be expected to prompt a high level of use of preventative measures.
The higher frequency of lit front or rear lights, and frequently both, may be related to the legal requirement and police monitoring. Since 1985, reflectors on pedals and rear mudguards have also been legal requirements.8 These were therefore excluded from observations of intentional use of reflective bodywear. Other reflective items, such as reflective cycle clips or strips on helmet, were not formally studied. The use, or otherwise, of helmet or clothing was unlikely to have been influenced by weather conditions. During the study, rain occurred only in the last 10 minutes.
Previous UK studies of helmet use have shown similar results. The overall UK rate in 1996 was estimated as 18% of cyclists, while studies in Oxford observed a higher rate of 24%.10,11 In Stafford, only 13% of senior high school cyclists wore one regularly.12 Studies of injured cyclists have recorded helmet use rates of 14% in South Wales13 and 11% in Cambridge.14 In other countries, less then one quarter of Australian teenagers reported regular use three years after introduction of legislation,15 while 22.9% of cyclists in urban Winnipeg wear one.16
Discounting direct head injuries, helmet use has been associated with a much lower incidence of severe injury (injury severity score >15) to the whole body.17 It has been suggested that non-use is a marker of a population of cyclists more likely to be involved in high impact crashes with motor vehicles, perhaps as a result of less safe cycling practices. This study supports the view that use of a cycling helmet is associated with higher use of pre-event phase equipment measures to avoid collision.
Traffic congestion in the UK is an ever increasing problem, with cycling a popular alternative. With increasing calls for control on pollution and inner city traffic levels, it is likely that other cities will find themselves required to support safer routes for cyclists. Oxford may be an atypical environment, because the university could provide a higher than average population of young adult cyclists. Studies of other urban and rural populations would allow validation of these findings on a wider scale.
Implications for prevention
Cycling helmet users in Oxford are significantly more likely to take precautions to increase their visibility in reduced lighting conditions. Cyclists taking measures to prevent injury in event of collision, are more likely to also take measures to appear more visible, and thus avoid such collisions. However, the majority remains at increased risk of high velocity impacts with motor vehicles.
Prevention of such impacts must be as high a priority as prevention of injuries once a collision has occurred. Effective traffic separation measures are becoming more widespread. The challenge now must be to promote collision prevention practices in cyclists themselves. Lessons may be learned from experience in the introduction and promotion of cycling helmets by approaches including education and legislation. As observed in this study, however, current health promotion tactics are meeting with an inadequate response from the cycling public. Continuing concerted efforts using a combination of strategies remains vital.