Having only visited L.A. a couple times…
could someone explain to me the logic behind the stop lights at some(?) of the on-ramps to L.A. freeways? 
How are they timed? Do they actually help drivers merge with the freeway traffic? At least when I saw them, they just seemed to quickly & uselessly flash red/green. How can they possibly account for different cars’ acceleration capability?
Try driving in Minneapolis/St. Paul, Phobos.
In this city, the originators of all things good for freeway use and niceness, you get to wait on the ramp for an easy 10-20 minutes to get on the freeway.
There have been attempts to get the things shut off and see what happens, but it never passes. The reasoning behind them is that they regulate traffic flow and speed up overall traffic on the freeway. A crock if you ask me, but they swear by their effectiveness.
If you’d like links and whatnot I can give 'em, it’s an issue I take close to the heart.
BTW, are you saying people in L.A. actually pay attention to these meters? Not very L.A. like, if you ask me.
Interesting. I had not seen them elsewhere. It seems ludicrous to me that one would come to a complete stop, just when you need lots of momentum to merge with high-speed traffic. Not all cars can go 0 to 60 in 2 seconds (and even if they could – that’s a big gas drain).
I am familiar with these lights. They are intended to keep you from reaching freeway speed when you are trying to merge, thereby slowing down freeway traffic as a whole.
Well, that’s all they end up doing.
It is ludicrous.
I happen to live next to a new section of freeway that is a major thoroughfare for the city (I-394).
When this section of freeway opened it was hailed as a ‘technological’ leap in freeway design. It cost millions to build. ‘Your traffic delays of the past have been fixed’ they said. It has cameras all over the place to control incoming and outgoing cars. Literally hundreds of camera’s in a ten mile jaunt.
Some guy at our university designed the software and cameras to ‘see’ traffic and control traffic flow accodingly. He had a big story in the paper and the nightly news when the section opened. He came out of the box talking about how ‘advanced’ and ‘revolutional’ his system was.
Since the day it opened, it’s been jammed non-stop from morning til night with traffic.
It also has the highest traveler per mile accident ratio of any other section of freeway in our area.
They didn’t have many stories on this university fellow after it opened.
But it’s always nice to know that you’re being watched on camera sitting in one massive traffic jam by engineer’s who’ve spent years ‘masturing’ this problem.
It really is a joke.
It’s also created alot of contoversy up here. Each year there are any number of bills to have this system of traffic control scrapped. But, somehow, it always dies in sesion. Alot of people covering their ass, if you ask me.
I just went to LA & you betcha, those things SUCK. As a matter of fact, I went through at least two red ones because I couldn’t stop in time.
The idea, as somebody said, is to prevent huge clusters of 10-15 cars from suddenly trying to merge on an already-slow freeway - supposedly this would only serve to make it even slower. It meters them, only allowing them to assault in waves of 1 or 2, depending on the particular on-ramp.
I can cite no studies, and really have nothing more than personal experience, but my guess is that they actually help. This puts me at odds with most, I believe. 
When traffic is only moving 25 mph (or less) on the freeway to begin with, accelerating to that speed from a dead stop is generally not a problem in the space they give you. It does, in my opinion, make the merge less horrific because you’re not fighting with 5 other merging vehicles at the same time.
If things are REALLY backed up, things can still get piled up in the merge, but I still think it’s not as bad as it would be without the metering lights.
I’m in the minority…flame away!
They’re designed to limit the number of cars per minute getting onto the freeways. I think they help, too. They’re only used when the freeways are already jammed, so you certainly don’t have to worry about accelerating. A brisk walking pace would be considered fast on most of the freeways during crunch times.
Kevin B.
I never really had a problem with them. Of course, I usually make a point to avoid the really bad traffic times. (Of course, you can’t always avoid bad traffic - that would be like avoiding breathing!)
Freeway meters do help even out the flow of cars coming on to a freeway. Traffic engineers are not putting them at onramps out of spite.
The newest interchanges in L.A. (from I-105 to I-405 or SR-110) use ramps also, but allow usually 2 or 3 cars per green. Unless traffic is already horrific, the meters usually do a decent job of keeping traffic from bunching up.
So how long before someone hijacks this thread and turns into a rant about carpool lanes?
I have also heard it is to keep people off the freeway. One of the constant questions in LA is “Should I take the Fwy or surface streets?” The metering signals add a “penalty function” to keep people from driving short (1 - 2 exit) trips on the freeway.
thanks everyone…the “logic” seems a little clearer now.
Is this limited to L.A. & Minneapolis/St. Paul? I have not seen this on the East Coast.
They tried these on the Lodge Expressway in Detroit around 1969 or 1970. I loved them. Then some idiot claimed that they were a way to help the suburbanites escape downtown Detroit at the expense of the local people and they were turned off (or allowed to malfunction out of existence) for a while.
I found that logic utterly stupid. I was going to school in the midst of a “blighted” neighborhood and I found that they allowed me easier entrance to the Lodge regardless whether I was “fleeing” to my parents’ suburban home or I was travelling to another “blighted” area to go shopping.
I was back on the Lodge last winter and was delighted to see them back in action.
As noted in earlier posts, they create a “pulse” effect for traffic entering the highway. Since there are no “clumps” of cars jamming their way into the right lane, that lane develops little pockets of clear space that the single entering car fits right into. (I am assuming that LA followed the Detroit model of putting the lights up near the top of the ramp to allow acceleration, not at the point where one merges.)
As KevinB said, the meters are only used when the freeway is already slow. It’s usually no problem to accellerate on the on-ramp… but then you have to slow down to merge!
One good thing about riding a motorcycle in California is that they’re easy to merge. And you can share lanes, so if the freeway is jammed you can keep going between any two lanes (but on neither of the shoulders). Keeps my air-cooled engine nice’n’cool (relatively speaking, of course. I wouldn’t want to touch it!) on those friggin’ hot So. Cal days.
The meters in LA are usually at the end of the onramp. I’ve never found this to be a big problem because the meters are usually only turned on during rush hours, so you don’t have to go from 0 to 55 in 3 seconds. The meters on the interchange from I-110 (Harbor) to I-105 (Century/Anderson) are in the middle of the interchange.
Of course, you could drive the Pasadena Freeway (Los Angeles’ oldest freeway) and get on one of the onramps that has a stop sign at the end of it and makes you turn directly on to the freeway with no place to accelerate. It’s exhilirating to do once you get the hang of it.
As for not allowing short hops on the freeway, I’ve never heard that. I often take short hops on freeways and even with the meter, it is normally faster than taking a surface street.
I’ve experienced them throughout the Puget Sound region, Portland, OR, and the Bay Area in California.
I thought they were a pretty common tool for regulating high volume onramps meeting busy (and slow) freeways.
I like them because they avoid one of the bigger acts of assholery I see drivers do:
Three cars (for example) are all on the onramp at the same time. The third car will merge early (crossing the solid white lines) and take the hole that would have gone to the first car. Then the second car will do it, taking up the next hole. This makes it harder for the first car to merge because the cars behind him on the ramp are taking the holes early.
They use them on Long Island, on the Long Island Expressway and I think the Northern and Southern State Parkways(I could be wrong about the parkways). They’re only turned on during rush hour. I don’t really drive a whole lot on the highways at that point so I couldn’t really tell you if they work or not.
and they’re a crock.
They come on when it’s detected that the main highway traffic is “optimal”. That is, any more traffic and things will slow down. So, they’re just trying to delay the inevitable: stopped traffic.
If the highway is at a complete standstill (or only going 10 mph max), the lights don’t come on. They figure that it’s not getting any better, so might as well let them on.
If any so-called expert would listen, there are two main factors that clog I-395 in Virginia:
[ol]
[li]In 10 miles, the lane count goes from 3 to 4 to 3 to 4 to 3. So you get a surge in traffic speed when it goes to 4 lanes, but then another crunch when that 4th lane has to re-merge. Make I-395 4 lanes all the way.[/li][li]The speed limit goes down to 40 mph once I-395 goes into the District of Columbia. When the traffic is saturated, a slow-down to that speed insures that someone is going to have to stop. If they’d designed the DC segment to be able to handle 55 mph, then traffice wouldn’t back up for the mile before the Potomac every @!#?@! morning![/li][/ol]
Boston’s solution to traffic jams…(1) during rush hour, open up the breakdown lanes to traffic (2) when that doesn’t work, spend $14 billion to put the roads underground where you can’t see the traffic