It is well established that an increase in number of cyclists in general leads to a relative reduction of the incidence rate of severe/fatal crashes involving cyclists, the so-called the safety in numbers phenomenon. Increased cycling can also lead to less motorised traffic and a corresponding decrease in traffic mishaps in general. Cycling in itself is not a threat to road safety, rather it is one of the healthiest activities that individuals can incorporate in their daily lives, in addition to having a positive impact on road safety.

Around 50% of motorised vehicle journeys are under 5km in length and 30% are under 3 km. This demonstrates the massive potential for transitioning from motorised transport to active modes of transport like cycling.

A significant barrier to increasing cycling's modal share however are the perceived safety risks associated with bicycles. It is important that cycling, in addition to actually being safe, appears safe and comfortable to the general public. The perception of risk and safety is therefore also an important element of cycling road safety and advocacy. Given the significant health benefits of cycling it is essential that we recognise the importance of cycling and walking as healthy, socially beneficial modes of transport.

As cycling and walking are active modes of transport they can contribute to a wide range of health benefits. Passive motorised transport only contributes to health costs due to emissions and crashes. The health benefits of active transport must be taken into account when promoting and implementing road safety interventions. Road safety interventions must not decrease the number of cyclists or act as a barrier to would-be cyclists as interventions will almost always result in a net loss for public health regardless of the effectiveness of the road safety measure.

Mandatory helmet legislation is an example of a traffic safety intervention which often has the effect of reducing the number of cyclists and thereby negating the overwhelming health benefits gained from an increase in cycling.