Analysis of Fuel Consumption and Emissions at Roundabout with Slip Lane, using SIDRA and Validation by MOVES Simulation

Abstract

SIDRA tool enables researchers and practitioners to model vehicle emissions at a project level. Vehicular fuel consumption and emissions performance (CO2 and CO) are simulated within single-lane roundabouts, with a one approach slip lane, under yield and free-flow exit control scenarios. Results are then compared to a roundabout with no slip lane, as a base, and all-way stop-controlled (AWSC) intersection within this experimental assessment. The MOVES (Motor Vehicle Emission Simulator) from EPA used to validate no slip lane roundabout as a base scenario. Results show that with a free-flow slip lane exit type, overall average total roundabout fuel consumption was reduced by 26%, CO2 emissions were reduced 27%, and CO emissions were reduced 17%, compared to an AWSC intersection. As expected, results indicate that a roundabout with and without slip lane shows a more significant reduction (improvement) of fuel consumption and pollutant emissions values than an AWSC intersection. Hence, the most effective roundabout performance in reducing delay, fuel consumption, and pollutant emissions generally is obtained from a free-flow slip lane.