Ramp meter on a freeway mainline?

[NE2]

WTF? Any more of these out there?

[english si]

A35 Red Bridge. Technically a signallised merge, rather than ramp metering, and not a freeway either, but similar...

[vdeane]

I-81 south at the Thousand Islands Bridge, in case of oversize vehicles crossing.

I-690 has its infamous traffic light, but that's not a ramp meter.

[roadfro]

California I-80 westbound, right after the Bay Bridge toll plaza.

[myosh_tino]

California I-80 westbound, right after the Bay Bridge toll plaza.

In that case, add westbound CA-92/San Mateo Bridge and westbound CA-84/Dumbarton Bridge.  These metering lights are just like the ones at the Bay Bridge and is supposed to meter traffic getting onto the bridges however, I'm not sure if these meters have every been turned on.

[Hot Rod Hootenanny]

For a very short time there was a traffic light/ramp meter for traffic coming south/west bound on I-670 (err, still signed I-71 at this time) into SB Oh 315 (technically unsigned at this time) in 1965 per the city of Columbus

The traffic light did not last long as state DOH demanded it removed.

[agentsteel53]

there are plenty of traffic lights on freeway-to-freeway connections.  not counting such things as CA-78 at I-5, or CA-56 at I-15, there are a few examples where the connection is direct, but there is a metering light.  I can't think of any offhand, though, but I think one of them connects to the 405.

[PAHighways]

I-376 at the eastbound and westbound Fort Pitt Tunnel portals and westbound Squirrel Hill Tunnel portal.

[TheHighwayMan3561]

I-376 at the eastbound and westbound Fort Pitt Tunnel portals and westbound Squirrel Hill Tunnel portal.

But are those ramp meters per se or are they just stoplights used in emergencies to keep traffic out of the tunnel when there's an accident or something?

[NE2]

The only one mentioned so far that's actually a ramp meter is the Ohio one. And that was technically on a ramp.

[PAHighways]

But are those ramp meters per se or are they just stoplights used in emergencies to keep traffic out of the tunnel when there's an accident or something?

I was stopped at the latter one day just a few weeks back and just made it through the yellow light at the outbound Fort Pitt Tunnel signals years ago.  In both cases there was no accident or any other impediment inside or at the other end of the tunnel.

[6a]

Those are all over the place in Atlanta now.

[NE2]

Those are all over the place in Atlanta now.

Ramp meters or ramp meters on the mainline?

[Bickendan]

Hmm... OR 217 at I-5 might be a stretch, where the mainlines shift from full freeway to suburban arterial AT the ramps to/from southbound I-5.

[roadfro]

The only one mentioned so far that's actually a ramp meter is the Ohio one. And that was technically on a ramp.

Well if you get technical...you can't have a "ramp meter" on a freeway mainline, cause the mainline wouldn't be a ramp...

[NE2]

A ramp meter is a type of signal that changes quickly between lanes, allowing alternate merging. It can exist on a non-ramp, just as a SPUI can be in a rural area.

[Alex]

I can only think of ramp meters on freeway to freeway connections, which are bad enough in their own right. See the ramps connecting I-105 and I-110 for instance.

[DBrim]

Not a meter, but worse.  I-90 at I-291 outside of Springfield, former home of one of the last state named interstate shields in MA. Ramp, to a T intersection with a light. To get on 291, you have to turn left.

[FreewayDan]

The westbound CA 94 mainlanes have a ramp meter at the CA 125 interchange.  An HOV lane is also present, but that lane has a ramp meter too.

https://www.aaroads.com/california/images094/ca-094_wb_exit_009a_05.jpg

[Kacie Jane]

I can only think of ramp meters on freeway to freeway connections, which are bad enough in their own right. See the ramps connecting I-105 and I-110 for instance.

Same here.  I can't recall which movements precisely, but a couple of the ramps at I-90/I-5 in Seattle have them.

[Mr_Northside]

I-376 at the eastbound and westbound Fort Pitt Tunnel portals and westbound Squirrel Hill Tunnel portal.

The eastbound Squirrel Hill tube got signals about a year & half ago... along with a lot more "Over-height Truck" warnings/directions, and attached to some of the preceding overhead BGS structures are lane signals (Green down arrow or Red "X")  
It's been over a year now since I saw them in action, but the lane signals were incorrectly used in conjunction with the traffic signal at the mouth of the tunnel.  (The green arrow would turn to a red "X", even though, technically the lane wasn't closed, just stopped at the mouth of the tunnel)

I was stopped at the latter one day just a few weeks back and just made it through the yellow light at the outbound Fort Pitt Tunnel signals years ago.  In both cases there was no accident or any other impediment inside or at the other end of the tunnel.

Chances are there was an over-height truck that needed turned around.  They'll shut down both tubes for that.  
I'd also bet they'll stop traffic when a vehicle needs to enter the parkway from the "median" at the mouth of the tunnel, rather than have them try to merge.

[andytom]

Hmm... OR 217 at I-5 might be a stretch, where the mainlines shift from full freeway to suburban arterial AT the ramps to/from southbound I-5.

No, that's just a standard traffic signal changing right-of-way between through traffic, crossing off-ramp traffic and left turning traffic.  Ramp meters are never used with crossing traffic: only with merging traffic to provide spacing for the merge.
http://maps.google.com/?ll=45.421462,-122.745242&spn=0.001563,0.003895&t=k&z=19

The one on the ramp from OR-217 to US-26 east qualifies for the secondary discussion here (ramp meters on freeway-to-freeway ramps).  It's turned off now because of the construction going on there (they just moved the ramp alignment onto the new roadway).  I'm not sure whether they will turn it back on or remove it when the project is complete.  At one time, it was needed (4 fwy lanes merging to 2 very quickly), but it really isn't needed any more (5 fwy lanes merging to 4).
http://maps.google.com/?ll=45.507001,-122.776361&spn=0.00156,0.003895&t=k&z=19

[Bickendan]

You're right. I remembered the OR 217/US 26 interchange after posting that.

[jprocknow]

I know this is old, but Milwaukee has them in all directions from U.S. 41/Wis 341 at the Stadium Freeway interchange.
I believe Phoenix has/had some as well, but don't know where.

[NE2]

I know this is old, but Milwaukee has them in all directions from U.S. 41/Wis 341 at the Stadium Freeway interchange.

On the ramps or the mainline?