9.4.1 The majority of non-motorcyclists might summarise the dynamic differences between motorcycles and other traffic as:“they accelerate faster and can get around traffic queues”. Both these things are true, but there is much more to the dynamics of motorcycles than two headline factors, and auditors need to be aware of other, subtler, dynamic differences to properly include the needs of motorcycle riders in the balancing of risks. It should always be foremost in an auditor’s mind that what may present a minor nuisance or a low risk, low severity hazard to a twin track vehicle driver,may present a low risk, high severity hazard to a motorcycle rider.

9.4.2 Most of the important dynamic differences between motorcycles and other vehicles arise from the way motorcycles make use of the laws of physics. For example, no other motor vehicles have wheels that can, indeed must,move significantly out of the vertical to enable manoeuvres such as cornering. At speed, the wheels behave like two large gyroscopes, adding a further dimension to their physical properties. A skilful rider can make good use of this gyroscopic effect. A novice will find it can produce unexpected effects. For example, on bends, applying the front brake can cause the machine to “sit up” and take a line tangential to the bend. From this it is easy to see why predictable and consistent bend geometry is critical to rider safety. For those involved in providing or maintaining the road infrastructure these dynamic differences mean that a motorcycle is not a kind of “two-wheeled car”.