Recent studies of truck parking demand and capacity constraints reflect a consensus that truck parking demand exceeds the available supply in many public rest areas and private truck stops nationwide. NCHRP Research Report 1137: Guide for Truck Parking Information Management Systems, from TRB's National Cooperative Highway Research Program, provides information on these systems that help address the need to provide safer parking options for commercial vehicle operators and reduce the time they take to search for parking through the collection and dissemination of real-time parking availability using a variety of technologies. Supplemental to the report is NCHRP Web-Only Document 415: Developing a Guide for Truck Parking Information Management Systems.