The conventional traffic sensors typically provide volume, occupancy, vehicle presence and speed data. Vehicle reidentification is an emerging advanced sensor technology that aims to provide more data for travel information, travel time estimation, vehicle classification, emission, and origin-destination (OD) estimation applications. Through a Small Business Innovation Research (SBIR) project sponsored by USDOT, we have demonstrated the potential of the technology. We are currently investigating its applications to both arterials and freeways in order to provide a more accurate traffic performance measurement system.