Many physically handicapped drivers have difficulties in using ordinary car controls, and modifications need to be made to their vehicles. A review of the types of adaptations and equipment that are available for this in Europe has identified the principal aspects that need to be considered in their design. For safety and ease of use, it is important to match the characteristics of a control conversion to the driver's capabilities, taking into account the location and mode of operation of the control, together with the operating forces and the range of movement. Many of these adaptations are highly individual, and it is also important to encourage innovation and flexibility in design to increase the possibilities for severely disabled people to obtain the mobility accepted as the norm by the rest of the population.

Modern technology permits the use of sophisticated control systems, and a high degree of power assistance can be provided on steering and brakes. This raises problems such as determining the appropriate degree of feedback or “feel” on the steering wheel for drivers who have little strength in their arms. More research is needed into drivers' responses using these types of controls. In more radical conversions, such as remote steering, there may be a choice of steering characteristic, and this also needs further study.