Coding of Road Information for Automated Highways

Communication of information from the roadway infrastructure to vehicles is expected to enhance Automated Highway Systems (AHS) by supporting subsystem functions like vehicle motion control, multiple vehicle coordination, and vehicle navigation. A suitable communication channel is information coding in the lateral reference used for automatic steering and lane keeping control, e.g. in the magnet reference system used by California Path (Partners for Advanced Transit and Highways). The presented coding strategy was designed for and tested at the I-15 test track near San Diego, CA, being prepared for the AHS demonstration of the National AHS Consortium (NAHSC) in 1997. A number of aspects are discussed, concerning types and structure of coded information, encoding and decoding schemes, and possible future extensions.