Caltrans to Be More Consistent in Placing Its On-Ramp Meters

Dear Readers:

In September, Street Smart had a column explaining how freeway on-ramp meters work. This week, on-ramp meters are again the topic, thanks to several related letters. Traffic analyst Joe El-Harake from the Caltrans Orange County office provides some enlightenment:

Dear Street Smart:

The car-pool lanes of most on-ramps are on the left. Sometimes, they are on the right. Why?

Dale E. Cornelison

Laguna Hills

It’s true. It can be hard knowing which on-ramp lane will be metered and which will be unmetered for use by car-poolers. However, the inconsistency will slowly come to a stop.

In the past, meters were placed in the lane most favored by drivers to increase compliance, El-Harake explained. For example, some ramps make a big loop as they drop down to the freeway. Many drivers will favor the right, inside lane, perhaps feeling that gravity pulls them into it.

If a meter was put in the left lane of these type ramps, then the many drivers who naturally favor the right lane would have to make a conscious effort to change into the left lane. By using the right lane, only the few car-poolers in the right lane and the few solo drivers in the left lane had to change lanes. The majority remained unaffected.

Now that meters are everywhere, the California Department of Transportation is more worried about consistency than compliance. All new meters will be placed in the right lane, and the left lane will be unchecked, El-Harake said. Also, when ramps with existing meters are revamped, those with signals on the left will have the lights moved to the right.

Dear Street Smart:

Recently while entering a freeway on a metered on-ramp, I noticed that the signs on each light post read “One Car Per Green” rather than the standard “One Car Per Green Each Lane.” Is it ever the case that the cars are supposed to alternate lanes, or was this probably an error?

Daniel Glenn Fisk

Buena Park

It was an error.

Dear Street Smart:

Metered freeway on-ramps that have two lanes get to be a drag race when the light turns green. I often let the car on the right go first, but there seems to be no protocol for two cars to go at the same time. Maybe this is not really a problem--the faster car gets on the freeway first. Certainly, if two lights alternated with a sign that said “This light for this lane only” or something, it might help.

David J. Bermani

Brea

Apparently what you suggest once posed quite a debate within Caltrans, according to El-Harake.

Some engineers favored having alternating signals, so that both drivers did not get a green light at the same time. However, other engineers felt that it was not worth the extra expense since they did not see a problem with both cars starting at the same time, El-Harake said.

Another proposal was to have “staggered” limit lines, so that one car would be slightly ahead of the other car when the light changed. This was a view El-Harake once favored.

Finally, one Caltrans engineer watched hours of videotape showing ramps with different types of meter setups, El-Harake said. The result? Nothing made a difference. If the car next to you wants to “win,” it will, it was found.

“An aggressive driver, you can’t design for,” El-Harake said.

Caltrans could try to develop some sort of protocol giving the right of way to the driver on the left or on the right. However, El-Harake said it is simpler and even safer to let drivers sort it out. For example, if rigid rules assigned right of way, a slow-poke driver might get to go first, only to have an aggressive driver zooming up from behind.

The rule now is to have the limit lines be even and let the lights go at the same time. However, there may be some places where this setup is different. As ramps are refurbished, limit lines and lights will be adjusted, El-Harake said.

Dear Street Smart:

Since most on-ramp meters are located two-thirds or more of the way down the ramp, this creates a situation in which the drivers must accelerate very quickly in the short length remaining in order to attain the same speed of the freeway traffic.

If one happens to be operating a vehicle that accelerates slowly, such as a loaded truck or a car with a trailer, this situation quickly becomes a hazard to both the freeway driver, who must brake to allow the slower vehicle to merge, and the on-ramp driver, who is trying to squeeze into the faster-moving traffic.

Often times, the merging vehicle is forced to use some of the shoulder at the end of the on-ramp to gain the extra speed needed to transition onto the roadway. A compromise of some type should be considered to alleviate this dangerous situation.

Richard Koehler

Westminster

El-Harake said that by and large, meters are positioned so that a vehicle still has enough time to reach freeway speed after leaving from a stop.

There are obviously exceptions, otherwise you would never have witnessed cars using the shoulder. But El-Harake said that’s exactly why there is a shoulder at the end of a ramp. It provides extra room for vehicles that, for whatever reason, fail to enter the freeway at the end of the ramp, he explained.

“If you feel you are in a situation where it is not safe to get in, that’s why we give you a shoulder,” El-Harake said.

El-Harake stressed that ramp meters have not been blamed for causing accidents and that getting up to speed shouldn’t be a problem. However, if you find a ramp where this is continually a problem in Orange County, then let Caltrans know so that it can be re-evaluated, El-Harake said.

Dear Street Smart:

I get on the new Costa Mesa Freeway extension at 22nd Street in Costa Mesa and go toward Riverside. On most mornings, the on-ramp lights are operating, sometimes backing traffic up onto Newport Boulevard. Since this is only the second on-ramp of the freeway, there are very few cars on the freeway. Why do they have the signal working when the freeway is nearly empty at this point?

Richard Loufek

Costa Mesa

Caltrans hears this question often. The freeway seems to be moving normally, so why bother metering?

El-Harake explained that this is because the meters are often left on because of traffic known to occur further ahead on a freeway. Where you jump on the freeway, everything may be moving. A mile ahead, it may be brake lights everywhere. By metering, Caltrans hopes to space out the impact on the existing congestion.