ISO 19377:2017 describes test methods for determining the deviation of the path travelled by a vehicle during a braking manoeuvre induced by an emergency braking system from a pre-defined desired path. The purpose of this document is the evaluation of the vehicle path during and following the system intervention. The corrective steering actions for keeping the vehicle on the desired path can be applied either by the driver or by a steering machine or by a driver assistance system. By making this document open for either open-loop or closed-loop testing, it is possible to apply the test method for evaluating how well the vehicle can be kept within user-defined lane markings after the system intervention, and also for evaluating the precision of the interaction between the emergency braking system and an active lane keeping system. This document applies to heavy vehicles equipped with an advanced emergency braking system (AEBS), including commercial vehicles, commercial vehicle combinations, buses and articulated buses as defined in ISO 3833 (trucks and trailers with maximum weight above 3,5 tonnes and buses and articulated buses with maximum weight above 5 tonnes, according to ECE and EC vehicle classification, categories M3, N2, N3, O3 and O4). NOTE The test method is intended to evaluate the entire vehicle behaviour, not for defining system requirements for the AEBS, which is done in the respective standards created by ISO/TC 204.