The hybrid electric vehicle (HEV) is already available commercially and is demonstrating the very significant benefit of improved fuel consumption. The costs associated with the hybrid vehicle are still high, and for novel types of auxiliary power unit are still undefined. Measures to improve the performance of HEV technology are emerging and include the traffic and navigation information which forms part of the telematics infrastructure. One of the key issues in enhancing HEV performance is journey prediction. Journey time and energy requirements can be products of a telematics system but form the basis for a significant performance enhancement to an HEV.