Ramp Metering

Some time ago I wrote about watching streams of traffic trying to enter the freeways in and around Vancouver. Platoons of vehicles would move through the acceleration lanes bumper to bumper and everyone would then try and jam themselves into the first gap in the slow lane that they encountered. Aside from being dangerous, the action contributes to the congestion that drivers are unhappy with in the first place because it causes traffic already on the freeway to slow.

Yesterday I had my first experience with ramp metering as my lane and the lane beside me joined a busy freeway. The beginning of each acceleration lane displayed a red light and stop line. Once we had stopped, the lights turned to green just long enough to allow one vehicle to proceed at a time, and the green lights for our adjacent lanes were staggered. This forced everyone to proper speed and alternating spacing  so that we joined the heavy stream of traffic just like the teeth in a zipper.

Yes, I was held up momentarily by the red light, but ultimately the average speed on the freeway I entered was higher and my total travel time was lower. I was also safer because ramp metering can be responsible for a 30% reduction in crashes compared to the same freeway without the system.

Perhaps this is an idea worth implementing in the Lower Mainland of British Columbia. It only operates when traffic is heavy, it is something that drivers do not need training to use and the cost of implementation may be offset by savings in travel time and a reduction in insurance claims.

Reference Links:

• Ramp Meters - Washington State Department of Transportation