Abstract
In a gap-acceptance entrance ramp control system, vehicles are released from a queue on a entrance ramp and are inserted into the gaps in the right lane of the freeway stream. For this system a gap threshold, T, is defined to be the minimum acceptable time- headway between vehicles in the outside lane into which a vehicle that is waiting on the ramp may attempt to merge. The gap threshold, T, determines, the dynamics of the ramp control process.