Car Drivers’ Skills and Attitudes to Motorcycle Safety: A Review

This report proposes a framework for interpreting the literature and evidence on car drivers’ skills and attitudes towards motorcyclists.

The framework relates attitudes, knowledge and skills/strategies to three behaviours: • Does the driver look at the motorcyclist?
• Does the driver realise that it is a motorcyclist?
• Does the driver correctly decide whether the motorcyclist poses a hazard?

The additional factor of stimulus-driven influences (‘bottom-up’ influences) is included in the framework.

The review of the literature first identifies a number of bottom-up factors such as A-frame obscuration, movement and conspicuity. One particular bottom-up influence seems especially relevant: spatial frequency (the width of the vehicle). Global Precedence theory suggests that we extract low spatial frequency items from a visual scene first (including wide vehicles such as cars). Thus we are more likely to miss narrow motorcycles, which are considered to be high spatial frequency items.

Whether a driver looks at a motorcycle can be dependent on many things including
experience and practice with particular road contexts, learned regularities of specific road environments, and the extent of peripheral vision.

Attitudes can indirectly influence whether drivers make all appropriate visual checks, and on the basis of the literature review it is suggested that speed may be an important mediating variable. If intentions to speed actually result in higher speeds, then visual search is constrained. Going through a junction at speed reduces the time available for appropriate visual checks.

Whether a driver realises that they are looking at a motorcycle is a more subtle question. In theory a driver could look directly at a motorcycle yet not perceive it. This is the truest form of the ‘Looked But Failed To See’ error (LBFTS). This again potentially relates to the spatial frequency of the motorcycle, but also to expectations and previous exposure.

Empathy with the motorcyclist’s plight appears important. Drivers with relatives who ride motorcycles have been reported to have fewer collisions with motorcyclists and have better observation skills in regard to motorcycles.

It is possible that a driver looks at an approaching motorcycle, and even perceives the motorcycle, yet still makes a manoeuvre that leads to a collision. This could occur because they misjudge whether it poses a potential risk, or fail to correctly appraise the approaching motorbike.

One of the key theories is the ‘size-arrival effect’. According to this theory, approaching speed is related to the size of the vehicle. The consequence of this is that the narrower image of the motorcycle compared to the car may result in the driver over-estimating the time of arrival.

The final conclusion summarises the factors of importance and argues for future directions for research in this area to help reduce motorcycle accidents on UK roads.