Specifies the data link layer and the physical layer of the VAN, a communications network up to 125 kbit/s, for road vehicle application. The VAN is an access-method oriented multimaster-multislave which allows optimized request/response management by special method of handling a remote transmission request (retaining access to the medium to allow insertion of a response). Defines the general architecture of the network and the content of the data link layer, and the physical layer for transmission between different types of electronic modules on board road vehicles.