Discussion on Session 4 „ACCIDENT“

PAPER

Question

“How do you explain the fact that more than a third of all motorcyclists surveyed had not applied their brakes at all before the impact? Was there only the time before the impact too short for a reaction? Could there be other reasons (blockage of action)? What is there?”

Answer by Elaine Hardy

There are many reasons why 1/3 of the riders did not use their brakes prior to impact. The most obvious is lack of time – consider that the perception/reaction time prior to collision is between 0.75 and 1.5 seconds. However also to consider is that 6% of the riders were stationary when they were hit by another vehicle. Another reason is lack of control – especially in the case of single vehicle crashes. I’m not sure what „blockage of action“ means, if it means that the rider froze – possibly. Also to consider is that there were a further n.107 riders who weren’t sure if they used their brakes or not. If you read the comments from the riders throughout the report, they offer quite a few responses as to what happened, including those that didn’t use their brakes.

PAPER

Question

How is the speed of the motorcycle taken into account? Are higher speeds than the permitted maximum speeds also taken into account?

Answer by Klemens Schwieger

Speed is considered relative to the mean driven speed of given driver and accelerations and decelerations are derived for this relative speed as well. It is an equal parameter to the yaw-, pitch- and roll-rates used in the estimation. The effects of the value of speed on the risk measurement are affected by the fact that drivers were asked to drive the tracks in 3 different modes (conservative, normal and dynamic), so that changes in speed would be more characteristic of particular road geometries rather than absolute values, since there would be data from each driver at different speeds for every meter on the track.

All driven speeds were taken into account and drivers were asked to remain within the given permitted maximum speeds.