Freeway ramp meters: Love ‘em or Hate ‘em?

[kang]

How do you feel about freeway ramp meters? You know what I am talking about: those signals at the end of a freeway on-ramp. They typically allow one car per green to enter the freeway, while the rest of the cars wait in a queue.

The idea is that they somehow increase the flow of traffic on the freeway downstream from the meter, but personally, I don’t see how they could possibly do anything except perhaps make merging onto the freeway at that particular ramp less congested, and even so, only in perfect freeway conditions for this. If the freeway is flowing smoothly, the ramp meter will have no effect on merging, as all cars can merge smoothly anyways. If the freeway is blocked, it won’t help with merging either, as the ramp meter will still allow more cars to enter the ramp than can merge onto the freeway, and you will still get congestion at the merge point.

Perhaps these ramp meters increase the flow of traffic on the freeway by keeping some number of cars on the ramp instead of on the freeway. I don’t see how this could work, as there is typically a very small number of cars on the ramp compared to the number of cars on the freeway.

There are times that the freeway is flowing quickly, and no one is on the ramp, yet the light is still red. This forces you to brake to a stop, right at the end of the ramp. When the light turns green, you must accelerate very quickly to match the speed of traffic on the freeway. This causes wear and tear on your brakes and clutch, and uses more gas and causes more pollution, than if the light were green (which it should be if no one is in the queue).

They recently added one of these to the freeway onramp I use for my morning commute. They must not have the timing right, as the traffic was jammed for several blocks behind the ramp. I was moving forward one car at a time for the duration. It increased my commute time by about 15 minutes, while also causing far more wear and tear on clutch and brakes, as I inched forward on car at a time. My left leg got tired! There were several hundred cars stuck in this queue during the 15 minutes I was there, which means there were probably several thousand throughout the morning. Think of how much additional gas was used, and how much additional smog was produced!

The worst part of all of this is that there was no improvement whatsoever on the flow of traffic on the freeway.

Freeway ramp meters: I hate ‘em!

[masraum]

Houston has them, but I almost never see them running.

[Rot 911]

I've never seen one.

[Porsche-O-Phile]

Totally dumb, IMHO. It's a band-aid on crappy highway design.

More stop-go instead of a smooth acceleration from a roll up to freeway speeds. Yeah. That makes sense.

[svandamme]

we have em here in the Netherlands, they are only on in certain conditions,
they do help when there is congestion, but not Jam yet

if to many cars at once go on the ramp , there's usually a problem getting the new cars to fluently blend with the highway traffic, especially if one or 2 trucks are on either highway, or ramp, or both, or an insecure driver , and then it piles up , and presto, full on jam

if they "trickle" in with this system , there is more time to get it right, and prevent a jam alltogether

[Joeaksa]

We have one where I get on the highway near my house and its always stuck on, day or night, does not matter what time it is. Course they never fix it...

[Porsche-O-Phile]

I never understood the point of having to slow down & stop, only to speed up again, only to stop when you get to the end of the on-ramp because the freeway is a parking lot anyway.

Complete waste of taxpayer $$$, IMO.

At major on-ramps where there's a crush of cars all trying to "pile on" at one time, then I can see the use, but that situation almost never happens. Usually it's one or two cars sitting there and that's it.

[MRM]

They shut them all off in Minneapolis a few years ago and traffic flow improved greatly. They turned some back on but have many fewer active. I think they can work but it's tricky to get the timing right and they usually don't help.

[island911]

Originally posted by Porsche-O-Phile
Totally dumb, IMHO. It's a band-aid on crappy highway design.

More stop-go instead of a smooth acceleration from a roll up to freeway speeds. Yeah. That makes sense.

ditto.

They are the result of "traffic engineers" convincing themselves how right they are because their expensive computer simulation says so.

[on2wheels52]

What's a freeway? Is it like the four lane bypass?
Jim