The rate at which cars are allowed onto the freeway is determined by the ramp volume, as well as the volume on the freeway. The mainline responsive controllers react to the volumes on the freeway, such that if the volumes decrease Significantly, then the meter will adjust and allow more cars onto the freeway. If the freeway volumes are very light, the meter may go to continuous green. Projects within freeway segments identified in the Ramp Meter Development Plan should include provisions for ramp metering. This cost as a percentage of the freeway construction varies depending on the type of freeway construction.
Ramp metering allows more vehicles to use the freeway.
Speeds also increase an average of 35 percent, while the accident rate decreases 40 percent with metering. Overall, this helps reduce fuel consumption, lessens air pollution and makes roadway travel more safe and efficient. Ramp metering controls the flow of traffic onto the freeway and reduces congestion in two ways. As traffic increases, the space between cars lessens and merging becomes increasingly difficult. When more than one car at a time enters the freeway, people have to jockey for position resulting in more congestion.