The ability to automatically collect more and better measurements of roadway assets (e.g., existence, condition, location, type) and to accurately map both geometry and elements of roadway assets is an important mitigating factor in roadway safety. This information serves numerous purposes including verification of road design codes, detecting degradation in roadway elements, detecting roadside hardware and clutter changes which impact safety (e.g., sight lines), creation of a roadway element inventory, analysis of accident data correlated to roadway inventory, and simulation of roadway conditions for safety analysis. To address the need to collect roadway information economically, accurately, and reliably, the Federal Highway Administration's (FHWA) Office of Advanced Research initiated the development of the Digital Highway Measurement System (DHMS) in 2003. The DHMS is a vehicle equipped with multiple sensors and instrumentation to collect road environment (roadway and roadside) geometry, roadside inventory, and pavement condition data at highway speeds. The DHMS vision is to enable, using state-of-the-art sensors and analysis, the collection of roadway geometry at required levels of accuracy not achievable by the current state-of-practice, and to introduce methods and metrics for capturing the presence, location, and health of all roadside assets.