Local Ramp Metering Strategy ALINEA: Microscopic Simulation Based Evaluation Study on Istanbul Freeways

Freeway networks are designed to provide a flexible flow of vehicles and uninterrupted routes especially in the metropolitan areas where the traffic volumes are considerably high. However; when the traffic volumes reach the highway capacity, speed differentials occur leading to phenomenon of congestion which either can be recurrent in peak hours or nonrecurrent in case of having an incident on the highway. Congestions are considered a case of matter as the freeway network performance is adversely affected in terms of reducing the speed, increasing the travel time, and increasing the vehicle emissions due to increase the fuel consumption. Also the distraction during congestion period, can increase the probability of accidents occurrence, where all drivers try to pass the congested segment of the freeway. For instance the structural solutions for congestion has become inefficient for economic, urban and environmental considerations. Thus, since 1960s the trend have been changed to control the link traffic and optimize its capacity by using coordinated and integrated surveillance and control strategies. For the recent decades ramp metering strategies are noticed to be an effective approach for controlling and managing the freeway traffic.