Pedestrian & Bicyclist Visibility

Fatalities among vulnerable road users, such as pedestrians and bicyclists, are up to 7 x more common at night than in the day. Reduced visibility is a leading cause of this increased crash risk at night, to a greater extent than other factors such as increased fatigue or alcohol use. Improving visibility of pedestrians and bicyclists at night-time is important in improving the safety of these vulnerable road users.

Our field-based studies have investigated various factors that affect the visibility of pedestrians and bicyclists at night or in other low-light conditions, and have developed a range of techniques to assess night-time driving performance on a closed-road circuit.

We have shown that drivers have more difficulty recognising and reacting to pedestrians and bicyclists under night than daytime conditions, and this effect is even more pronounced among older drivers.  However, when pedestrians wear retro-reflective materials on their moveable joints (biological motion, or “biomotion”), visibility is greatly enhanced for both young and older drivers.

Pedestrian Safety at Night

 

Pedestrians are up to 7 x more likely to be involved in a collision at night-time compared to the day. The research team has undertaken a series of studies that have investigated factors affecting pedestrian visibility and ways in which pedestrians could be made more conspicuous at night-time.  These studies demonstrated that older drivers had significantly greater difficulty recognizing roadside pedestrians than younger drivers, the benefits of high beam headlights and that clothing has a significant impact on the distance at which an oncoming driver first recognised the presence of pedestrians and cyclists.  We showed that clothing involving reflective strips in a biomotion configuration (on the moveable joints) has significant benefits for both pedestrian and cyclist night-time visibility, increasing the distance at which drivers first recognise pedestrians and cyclists by a factor of up to 3x relative to that for a vest containing the same amount of retroreflective material. Importantly, these studies demonstrated that these clothing configurations are robust to the effects of clutter in the environment, oncoming glare and are less affected by cataracts and optical blur than other types of clothing. Eye movement studies also provided insight into how biomotion clothing facilitated these longer recognition distances.

The findings regarding night-time pedestrian visibility have been used to change Australian and New Zealand Standard (AS/NZS 4602.1:2011) for high visibility clothing at night-time as well as the standards governing high visibility clothing for traffic controllers to incorporate retroreflective material on the moveable joints in a biomotion configuration.

Bicyclist Safety at Night

Bicyclists are among the most vulnerable of road users, both in terms of their chance of being involved in a crash or near miss, as well as in the severity of any resulting injuries. A number of studies suggest that drivers do not detect bicyclists until it is too late to avoid a collision, which suggests that poor visibility or conspicuity may be an important contributing factor to their crash involvement.  We have conducted a series of studies to determine the factors associated with bicyclist crashes at night-time and to identify ways in which cyclist visibility and hence safety can be improved. These studies have demonstrated that adding retro-reflective strips in a modified biomotion configuration (ankles and knees) increases visibility distances by 6x compared to a condition with no retro-reflective markings.  In a separate study, participants cycled in place at night-time and were asked to estimate their own conspicuity for different bicycle light and clothing configurations. Overall, bicyclists overestimated their own visibility compared to the previously collected recognition distances and underestimated the visibility benefits of retroreflective markings on their ankles and knees in the modified ‘biomotion’ configuration. Participants also mistakenly judged that a fluorescent vest, that did not include retroreflective material, would enhance their night-time conspicuity. These findings suggest that bicyclists misjudge the magnitude of the night-time conspicuity problem and the potential value of conspicuity treatments.

 


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Team

Publications