Recent years have seen a major push for better safety for the people who work and drive on roads that are under construction, and it is now standard to see 40 km/h speed limits in work zones.
Bike riders also travel through work zones on roads and are exposed to risk; should they also be ask to ride slower and take more care?
Researchers in Sweden, responding to concerns that present guidelines do not take bike riders and pedestrians into sufficient consideration, wondered whether speed reduction interventions could help.
About four per cent of single bike crashes in Sweden are in road work zones with bike riders falling when encountering cables, hoses, pipes etc. laid across the bike path; loose gravel, stones or dirt from the road works; high and/or unmarked edges; large potholes, ditches or other irregularities.
The researchers believed that speed management – reducing both the absolute speed and the speed variance among riders – could reduce crashes and impacts, but questioned how best to achieve the speed reduction?
A 300 metre test circuit was prepared with several potential interventions –chicanes, rumble mats, optically patterned stripes, and a soft, wheel-resistant mat.
A group of participants had their bikes equipped with cameras and two riders were fitted with eye-tracking equipment.
One observation was that the rumble mat and the chicane slowed bikes too much, to the point of instability below 10 km/h.
None of the interventions reduced absolute cycling speed sustainably, while all interventions had similar temporary effects on cycling speed.
The mean speed was reduced in the first encounter, but this effect was short-lived, with mean speeds returning to approximately baseline values after one or two encounters.
As riders became more familiar with the interventions, they sped up again.
The soft mat was generally perceived positively by the riders, not only for comfort and perceived risk, but also for its speed reducing effect.
For the soft mat, many participants reported exerting extra effort, which reduced or cancelled out the speed reduction. This indicates that bike riders are unwilling to lose momentum and rather put in some more effort at least briefly to maintain their desired speed.
The researchers concluded nevertheless, that of the interventions tested the soft mat can be considered the most promising intervention for reducing the speed of bike riders, without impaired comfort or increased crash risk.
"In a real work zone situation, it is possible that the increased rolling resistance of the soft mat could be an effective and relatively safe way to raise cyclists’ awareness of an oncoming situation where a reduced speed is recommended,” they said.
Or become our friend and subscribe to receive our fortnightly newsletter.