The Highway-Rail Crossing Handbook, 3rd Edition (Handbook) has been prepared to disseminate current practices and requirements for developing engineering treatments for highway-rail grade crossings (referred to herein as "crossings"). The Handbook is intended to provide practitioners of all levels of knowledge and experience with critical background information and "noteworthy practices" consistent with the 2009 Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) and more recent guidance developed by recognized subject matter experts. This edition constitutes a substantial update to and revision of the 2007 Handbook and efforts have been made to reorganize the contents.