Roadscapes Wednesday: Ramp Metering

By Nathan Young on November 28, 2012

I wanted to something different for Roadscapes Wednesday this week. Many metro areas have ramp meters on the on-ramps along freeways. In the southeast; Georgia, Louisiana, and Florida have them in the big cities. But I have always wondered why Alabama and ALDOT doesn’t use ramp meters along the freeways in Birmingham. When you are driving on an interstate. Don’t you hate it when you see a bunch of traffic attempting to merge on all at one time. This especially happens when traffic gets the left turn green signal.

Ramp meters controls the amount of traffic that enters a freeway. Instead of having a bunch of traffic merging at once. You get a steady flow of traffic attempting to merge on. This is much safer than having many cars competing to get on the freeway. Having ramp meters also keeps the traffic moving on freeways instead of slowing down to merging traffic. Many cities around the world use ramp meters to control the amount of traffic onto freeways. And the question I ask is why does ALDOT not use them?

When I go to the Birmingham Metro I dread seeing a bunch of cars that are about to merge on. Sometimes I might see the traffic light turn green for traffic wanting to get on the interstate. When I see a bunch of traffic about to merge on I will either speed up to get in front of the traffic. Or I will attempt to get in the left lane very quickly. Even if that means cutting someone off. It’s better than getting stuck behind someone going slow and not merging onto the freeway properly.

The biggest issue with ramp meters is on-ramp traffic backing up onto the surface street. Many states have sensors installed so when traffic is backed up onto the surface street, the ramp meter will temporary turn off. Also, the ramp meters are not on 24/7. They are only on during the rush hour. And if traffic during rush hour is not heavy, the ramp meters will turn off. By controlling the flow of cars, ramp meters actually allow more cars to use the freeway. And I think Alabama and ALDOT needs to install them along the Birmingham freeways. This idea would make traffic in Birmingham flow better!