One vehicle per green metering permits vehicles to enter the freeway one-by-one, as vehicles are detected. When a vehicle approaches the ramp meter, it passes over the presence or demand detector which notifies the signal to turn green. As a vehicle passes over the passage detector, the signal is then notified to terminate the green cycle. If a vehicle is not present on the demand detector, the signal indication remains red until a vehicle is detected. One vehicle per green metering has a capacity of 900 vehicles per hour (veh /h). If a capacity greater than 900 veh/h is desired, a multiple vehicle per green approach may be suitable