The primary objective of this research effort was to compare roadside data collected by typical manual methods – on foot and often requiring traffic control – to data collected by manned data collection vehicles moving with traffic. The research team provided an unbiased comparison of multiple vendors collecting many types of data on various roadway elements including curb, guardrail, signs, pavement markings, and roadway geometry. The results showed that mobile data compared reasonably well to manual data for most of the desired variables.Among the major lessons learned is the need for crystal clear specifications before embarking on a mobile data collection program