In recent times there has been an increase in the development, availability and use of small, motorised vehicles that may be alternatives to more conventional modes of personal transport such as bicycles or cars. Much of the interest in these 'alternative vehicles' (AV) is in their perceived benefits for pollution and congestion reduction.

To date there has been no uniform global approach to rules and standards governing the use of AVs. Regional requirements have mostly been applied on an ad hoc basis, differing significantly between jurisdictions. This has led to a highly prescriptive approach. This has tended to constrain innovative design, often because the vehicle concerned does not meet a regulatory definition.

In many jurisdictions there appears to be confusion amongst retailers, suppliers, consumers and enforcement agencies as to what types of AV may be legal and what rules govern their use. The differences between jurisdictions also mean that manufacturers and suppliers cannot easily design a single vehicle to market in a number of regions.

We review the types of AV that are available, or are under development, the limitations of the infrastructure on which they might be used and the safety issues arising from a mix of conventional road/path users and AVs.