Estimating the required braking distance on the motorcycle during an emergency manoeuvre: this is the subject of the latest study by the German Institute for Two-Wheeler Safety (ifz). The fact that a large proportion of motorcyclists reach their limits here is shown by the results of the practical study carried out by the ifz.

About one in two motorcyclists misjudges the required braking distance and needs more distance to brake than previously estimated. This is one of the central findings of the recently published and thus most recent ifz study “Limits of Perception When Braking – Estimation and Reality of Braking Distances with the Motorcycle in Comparison”.

The visibility estimates of the braking distances were “checked” by the test subjects through their own emergency braking with the motorcycle in over 200 trips. The comparison of the two results: Depending on the speed, 46 to 54 percent of the participants needed a longer braking distance than previously assumed. With increasing speed, the uncertainty in the estimates increases significantly.

“Most participants find it rather difficult to correctly estimate the required braking distances at different speeds, which they also confirm themselves,” says André Lang, head of research ifz. As a basis for their estimates, 58 percent state the ‘gut feeling’. The study also provides evidence of positive effects of regular exercise. “Practicing emergency braking tends to be accompanied by shorter real braking distances,” Lang sums up. Knowledge of the functionality of your own brake system on the motorcycle also promotes better results in terms of shorter braking distances.

André Lang emphasizes another interesting aspect with regard to annual kilometres driven: “Contrary to assumption, frequent drivers do not estimate braking distances more reliably than infrequent drivers.” The same applies when looking at the driver’s age. “With increasing age, braking distances tended to be longer, but this could lead to longer distances in everyday driving,” the research manager continues.

The study results also show a fundamental perception problem in the concrete estimation of distances: The participants first determined a distance purely visually on the test track and were then asked to quantify how many meters they estimated this distance was. This revealed a clear discrepancy between visual perception and meter information. On average, the participants considered the actual distance to be longer than it really was. As the speed increased, these deviations increased significantly.

This finding is particularly relevant for road traffic. For example, if you overestimate an existing distance, you may believe that you are keeping a distance of 50 meters, even though it is actually significantly less. “Supposed 50 meters distance can perhaps only be 30 meters in reality,” Lang sums up the perception problem. One possible consequence: road users believe that they are keeping a sufficient distance, although the actual distance is smaller than assumed.

Thanks to fifty committed motorcyclists who took part in the ifz study on the grounds of the ADAC traffic training area in Recklinghausen, it can be said that estimating the necessary braking distance is difficult even for experienced motorcyclists. Routine and driving practice alone are not necessarily enough to reliably assess braking distances. Regular emergency braking exercises and driving safety training as well as dealing with the topic of braking prove to be beneficial.

Further results and the study itself can be found here: Limits of perception when braking.

Source: ifz