Sufficient grip is crucial for motorcycles, because motorcycles (normally) have just two wheels: lose grip with one and you are already in trouble. Losing grip not only means sliding but also possible loss of balance and a crash. This is why it is important that the skid resistance measurements of the road authorities meet our needs too, which isn’t the case now.

FEMA’s Dolf Willigers and SMC’s Maria Nordqvist have written a technical report, which includes clear recommendations to road authorities on how to test and improve road friction.

Loss of grip can occur when a road surface has lost some of its friction because of wear, because of the weather (water, snow, ice) and because of bitumen bleeding, badly executed repairs, manhole covers, road markings, wrong choice of aggregate, gravel, spillage and similar. Uncontrolled skidding due to inadequate surface friction and poor visibility due to splash and spray have been found to be the two primary causes of wet weather crashes with skidding alone contributing to 15% to 35% of all wet weather crashes.

There is a need for new and improved methods to measure the road surface skid resistance. Partially, and in the future perhaps entirely, this could be solved by making use of camera- and 3-D scans as are already used in several countries.

The report ‘Road surface friction and motorcycling’ can be found here.

Written by Dolf Willigers

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