California Partners for Advanced Transportation Technology

This report assesses the ability of the emission estimating algorithms contained in version 4 of the CALINE line source dispersion model developed by Caltrans (CALINE 4) to accurately predict carbon monoxide emissions from a fleet of motor vehicles. The CALINE 4 model contains algorithms that predict carbon monoxide emissions from discrete modal events of idle, cruise, acceleration, and deceleration. The modified CALINE 4 model algorithms are used to predict CO impacts of an applied intelligent vehicle and highway system concept, automatic vehicle identification applied to electronic tolling operations. The analyses show that electronic tolling in place of conventional toll plazas offers significant CO reductions under three different operating scenarios. The authors conclude that under certain applications, Intelligent Vehicle Highway Systems (IVHS) technologies can be beneficial to air quality.