A typical convoy (photo of solar car by Jorrit Lousberg, from here)
Solar cars in the WSC each form part of a convoy – a typical convoy is shown above (click to zoom). The lead (front) escort vehicle and chase (rear) escort vehicle ride immediately in front of and immediately behind the solar car. The chase vehicle carries a warning sign (“CAUTION: SOLAR VEHICLE AHEAD”) that informs other traffic about the presence of the solar car. In addition, the chase vehicle carries emergency equipment like fire extinguishers and a first-aid kit.
The truck (or car with a trailer) rides further behind. It carries equipment and provides the ability to transport the solar car in the event of a breakdown.
The (optional) scout vehicle rides well ahead, checking out road conditions and potential hazards. There may also be additional vehicles, like a media car. All vehicles in the convoy stay in touch with each other using CB radio.
See also this excellent post by Solar Team Twente about their 11-vehicle convoy, illustrated in the infographic below (click to zoom). As is often the case, their chase (rear) escort vehicle also houses the team’s Decision-Making Unit (DMU), who plan the strategy for the race.