Greenfield Bridge (Homestead, Oakland: school, closing, live in)

[Craziaskowboi]

Originally Posted by sskink

That should happen regardless. I still don't get why drivers here can't figure out how to merge in and out smoothly in that 1/4 mile before the tunnel, but since they obviously can't, it's gotta move. There's no reason mid-afternoon traffic should be backed up to the Blvd of Allies entrance ramp.

No, it's gotta move because there's a STOP sign at the end of it, and then people have to floor the accelerator and do a double lane change in 500 feet in order to keep from exiting the highway again because the first lane they merge into says EXIT ONLY. That eastbound on-ramp is a disgrace to the Eisenhower Interstate Highway System.

[BrianTH]

Originally Posted by SteelCityRising

No, but the detour route will most likely take you up South Braddock Avenue through Regent Square to Forbes Avenue in Squirrel Hill.

I suppose that is possible, but it could also take people off at Squirrel Hill, and go down Beechwood/Greenfield/Second Avenue.

Edit: The article says it will be closed between Squirrel Hill and Bates, which I interpret as allowing people to get to Squirrel Hill before detouring.

[I_Like_Spam]

Originally Posted by BrianTH

I suppose that is possible, but it could also take people off at Squirrel Hill, and go down Beechwood/Greenfield/Second Avenue.

Official detours are only suggested routes and people will, in the end, find their own way.

If people are backed through the tunnel trying to get off at Squirrel Hill, a lot will try to get off at Braddock Avenue or Wilkinsburg to figure their own way to their ultimate destination.

Should be a mess.

[BrianTH]

Originally Posted by I_Like_Spam

Official detours are only suggested routes and people will, in the end, find their own way. If people are backed through the tunnel trying to get off at Squirrel Hill, a lot will try to get off at Braddock Avenue or Wilkinsburg to figure their own way to their ultimate destination.

Oh sure. But not all that many people get off on Braddock now despite the tunnel traffic, and I think that is because you have already been in the tunnel traffic for quite a while before then. I suspect this will be similar--if people aren't planning to go all the way to Squirrel Hill, they will mostly not try to get to Braddock either.

[greg42]

Originally Posted by BrianTH

The article says it will be closed between Squirrel Hill and Bates, which I interpret as allowing people to get to Squirrel Hill before detouring.

Finally, a real reason for the Squirrel Hill Tunnel to be backed up!

[Impala26]

Sorry to resurrect an old thread, but this has been bugging me lately...

I had always suspected that one of the main culprits to the chronic Parkway EAst tunnel backups, at least OUTBOUND, was the utterly outrageous layout of the Squirrel Hill interchange. Specifically, I'm referring to the eastbound on-ramp that shoots off from Beechwood Boulevard. Words cannot express how truly horrifically designed this ramp is.

First and foremost, this ramp is one of those 50's/60's era ramps that literally have no merge lane and have you come to complete stop. As if trying to catch up with thick 55-65 mph traffic from a dead stop isn't bad enough, the ramp has horrible sight-lines, as the highway is climbing AND coming around a bend in the valley. Even all this though sounds manageable before you factor in the fact that once you have successfully found yourself in the traffic lane, you must now merge over AGAIN... IMMEDIATELY... IN 800 FEET or be forced off the parkway in an exit only lane. The logistics of this merge maneuver are staggering (not to mention the engineering that went in to it). That is just tried and true BAD HIGHWAY ENGINEERING, even by 1950's standards.

So, my proposal would be to just see what would happen to traffic if this ONE ramp were closed. Without all the suicide-merging constantly going on I can imagine that, while traffic would still back up, it could likely move a lot more smoothly.

I have lots of other fantastical ideas for "fixing" this interchange that doesn't involve widening the tunnels, such as making a new partial interchange with the new bridge to replace the Greenfield Bridge. Another idea was to have a new eastbound on-ramp descend onto the middle of the Parkway that would maintain its own lane (left lane), with a middle pass-through lane, and a right exit-only lane (presuming the highway smushes to two lanes prior to here.

Point is, there is no way that the current interchange is up to ANY code, let alone interstate standards.

[Geeo]

That interchange is horrific. It was opened in 1953, a few years before the interstate highway program came into being in 1956 under Eisenhower. Look up some old pictures from the 50s of the parkway and you'll see very light traffic. There was very little residential development past Wilkinsburg, so the highway was probably adequate for a few years. Then came the suburban explosion of Monroeville and further out.

[norcider]

I'd head down Greenfield to Swinburn bridge and up to Blvd of Allies, but lots of people use that now as it is so I'm sure that route will become congested.

[Stijl Council]

Originally Posted by sskink

That should happen regardless. I still don't get why drivers here can't figure out how to merge in and out smoothly in that 1/4 mile before the tunnel, but since they obviously can't, it's gotta move. There's no reason mid-afternoon traffic should be backed up to the Blvd of Allies entrance ramp.

The stop sign at the end of the on-ramp really doesn't help.

[Craziaskowboi]

Originally Posted by Impala26

I have lots of other fantastical ideas for "fixing" this interchange that doesn't involve widening the tunnels, such as making a new partial interchange with the new bridge to replace the Greenfield Bridge.

Here's the existing Squirrel Hill/Homestead interchange:




And here's a crude illustration of how I'd fix it:




The new eastbound off-ramp is shaded GREEN. The new eastbound on-ramp is shaded BLUE. The new westbound off-ramp is shaded RED. The new westbound on-ramp is shaded YELLOW. Infrastructure that would be removed is covered in BLACK. Ramp geometry would be configured assuming the Parkway East has a right-of-way that's 122' wide.