Adjusting HCM 2010 freeway density formula to consider ramp metering in merge areas

Although ramp meters are introduced more than half a century ago, still there is not any proposed method in Highway Capacity Manual to calculate Level of Service in a freewayand on-ramp junction area. In this study, it is tried to simulate such a junction and find adjustment factors to compute freeway LOS right after an on-ramp junction when thevehicles entrance to the freeway is controlled by a ramp meter. CORSIM software is used assimulation software and different situation are considered to find various adjustment factors. Finally, the algorithm for proposed method is reported and to facilitate using adjustment factors, a visual basic application is coded

Keywords:

Ramp control , Highway capacity manual , Freeway , Ramp , Adjustment