California Partners for Advanced Transportation Technology

This study undertakes an evaluation of the benefits and costs of ramp metering. The primary purpose was to provide empirical information on the value of the introduction and use of this form of ITS technology. Three cases are examined in the analysis. The impact of ramp metering on traffic behavior is simulated based on a cell transmission model and an assumed travel demand on the freeway as well as the ramp. Temporal travel demand change is determined based on the average travel pattern obtained from the I-880 freeway database. Isolated, single traffic responsive ramp metering is assumed. We identify and quantify the benefits and costs based on established assumptions, and finally analyzed economic value of ramp metering. Benefits of ramp metering are derived based on travel time value and fuel consumption and by savings in travel delay. In this study, it turns out that there is a net increase in vehicle emissions as a result of with ramp metering.