This SAE Recommended Practice establishes a uniform, powered vehicle test procedure and minimum performance requirement for lane departure warning systems used in highway trucks and buses greater than 4546 kg (10000 pounds) GVW. Systems similar in function but different in scope and complexity, including Lane Keeping/Lane Assist and Merge Assist, are not included in this document. This document does not apply to trailers, dollies, etc. This document does not intend to exclude any particular system or sensor technology. The specification will test the functionality of the LDWS (e.g., ability to detect lane presence, and ability to detect an unintended lane departure), its ability to indicate LDWS engagement, its ability to indicate LDWS disengagement, and determine the point at which the LDWS notifies the Human Machine Interface (HMI) or vehicle control system that a lane departure event is detected. Moreover, the specification determines whether a system performs at a minimally acceptable level. The HMI is not addressed herein but is considered in SAE Standard J2808.