Pudding Street Interchange Project

[cl94]

The Taconic, Sprain, and Bronx River Parkways generally provide a limited-access route between I-84 in Dutchess County and I-278 in The Bronx. Except, there's one at-grade intersection with a real road: Pudding Street. While most at-grades along the Taconic have been turned into RIROs, Pudding Street has cross traffic because the alternate requires a 20-minute detour. Starting a few months from now, that's going to change.

Pudding Street is being upgraded to a diamond interchange, bringing the cross traffic to an end. During part of construction, Pudding Street will be closed at the Taconic with no access. Pudding Street is being realigned for a short distance west of the Taconic. There's going to be a decent amount of earthwork and rock cutting, but minimal property acquisition. Plans are here.

[froggie]

^ Do they have a simple layout map?

[cl94]

^ Do they have a simple layout map?

Annoyingly, there is not a good layout map that I can find anywhere, either in the contract documents or other published material. The best we have is this diagram from the plans.



They're moving the carriageways closer together and realigning Pudding Street to the north. This sheet from the plans probably gives the best explanation of the new alignments.



The southbound entrance ramp is just off of the sheet to the bottom left.

[empirestate]

By way of update, the overpass is now largely complete, and stands in the existing wide median, with traffic shifted just slightly around it on the existing carriageways.

The SB onramp is complete, having been cut through the earth there, and at present handles traffic on the west side of Pudding Street, via a temporary RIRO where the ramp joins.

Excavation is underway for the SB offramp, but has a ways to go yet.

Progress on the east side wasn't very apparent; my guess is that they will shunt NB traffic onto one of the new carriageways before starting on the NB ramps.

[TheDon102]

I drove by it today, and it looks great, apparently construction is supposed to end summer of next year but they've made a lot of progress from what I can tell.

Unrelated but when is NYSDOT gonna widen this thing to 6 lanes to at least I-84? Unfortunately the Taconic is becoming less of a scenic byway and more of a commuter freeway... I understand thats probably gonna require a different alignment (kinda like they did in Westchester), but I think its warranted.

[empirestate]

Unrelated but when is NYSDOT gonna widen this thing to 6 lanes to at least I-84? Unfortunately the Taconic is becoming less of a scenic byway and more of a commuter freeway... I understand thats probably gonna require a different alignment (kinda like they did in Westchester), but I think its warranted.

Not that it's by any means imminent, but at this point I'd rather see a relief route along the US 9 corridor than continual upgrades to the Taconic. Or, more generally, find ways to make it less necessary to commute on the Taconic.

[TheDon102]

Unrelated but when is NYSDOT gonna widen this thing to 6 lanes to at least I-84? Unfortunately the Taconic is becoming less of a scenic byway and more of a commuter freeway... I understand thats probably gonna require a different alignment (kinda like they did in Westchester), but I think its warranted.

Not that it's by any means imminent, but at this point I'd rather see a relief route along the US 9 corridor than continual upgrades to the Taconic. Or, more generally, find ways to make it less necessary to commute on the Taconic.

I-487 was the solution to the problems on the US 9 corridor and its cancellation necessitates the gradual freeway upgrades to the Taconic. There is no way (at least now) that a controlled access freeway on a new alignment can be built in Westchester County. The only thing you can do now is upgrade the Taconic.

[empirestate]

I-487 was the solution to the problems on the US 9 corridor and its cancellation necessitates the gradual freeway upgrades to the Taconic. There is no way (at least now) that a controlled access freeway on a new alignment can be built in Westchester County. The only thing you can do now is upgrade the Taconic.

Right, I-487 is the type of solution I'm referring to. However, it may not be entirely controlled access. (It may not entirely be a new roadway at all.)

[crispy93]

Unrelated but when is NYSDOT gonna widen this thing to 6 lanes to at least I-84? Unfortunately the Taconic is becoming less of a scenic byway and more of a commuter freeway... I understand thats probably gonna require a different alignment (kinda like they did in Westchester), but I think its warranted.

I think the segment in Westchester was originally a single carriageway (like in Putnam) and the southbound carriageway was built in stages to modernize it. Annoyingly, the speed limit is still 55 (apparently the curves don't meet interstate highway standards, but only cars can use this road so...). A new carriageway would probably have to be built and that would require some excavation on that retaining wall near Peekskill Hollow Road, and then it would have to go around that nasty curve between PHR and Pudding Street. IIRC, a tunnel was proposed in the 60s but defeated by local opposition.

I did always find it interesting that just before NY 301, the northbound carriageway is much curvier than the southbound one, you can even see it on a map. That 301 interchange is so bizarre, it's like a dangerous budget cloverleaf for a state road that doesn't see much volume: https://www.google.com/maps/@41.4671357,-73.8236217,16.36z

[Rothman]

55 mph is an appropriate speed limit in this area.

[crispy93]

55 mph is an appropriate speed limit in this area.

I've always wondered, how do engineers reconcile design speed vs. speed limit? I found this old specification sheet that says (at least one segment of) the TSP has a 65 mph design speed in Westchester: https://i.imgur.com/xi5xsV9.png. That is, why design a 65 mph highway only to post it at a lower speed? Or maybe I misunderstand what design speed is. Thanks!

[Duke87]

I've always wondered, how do engineers reconcile design speed vs. speed limit? I found this old specification sheet that says (at least one segment of) the TSP has a 65 mph design speed in Westchester: https://i.imgur.com/xi5xsV9.png. That is, why design a 65 mph highway only to post it at a lower speed? Or maybe I misunderstand what design speed is. Thanks!

It's common practice to have a design speed higher than the posted limit by 5-10 MPH purely for the sake of having a factor of safety built in. Look at it this way: if your calculations say it's unsafe to drive 66 MPH, telling people it's okay to go 65 leaves no room for error.

Of course this is part of why driving 5-10 MPH over the posted speed limit so often feels perfectly safe - because speed limits are usually set deliberately conservatively.

[Ketchup99]

I've always wondered, how do engineers reconcile design speed vs. speed limit? I found this old specification sheet that says (at least one segment of) the TSP has a 65 mph design speed in Westchester: https://i.imgur.com/xi5xsV9.png. That is, why design a 65 mph highway only to post it at a lower speed? Or maybe I misunderstand what design speed is. Thanks!

It's common practice to have a design speed higher than the posted limit by 5-10 MPH purely for the sake of having a factor of safety built in. Look at it this way: if your calculations say it's unsafe to drive 66 MPH, telling people it's okay to go 65 leaves no room for error.

Of course this is part of why driving 5-10 MPH over the posted speed limit so often feels perfectly safe - because speed limits are usually set deliberately conservatively.

That's why American speed limits are so dumb - they don't tell you at all what the actual speed limit is. They throw a random number out, say "we'll pull you over for either 5 or 15 over, depending on how broke we are" and don't actually tell you the maximum safe speed. If the limit was actually the limit - the fastest you can safely drive - and it was set at 65 (and this system was in effect nationwide), people would comply because they know what the limit means.

[Bitmapped]

I've always wondered, how do engineers reconcile design speed vs. speed limit? I found this old specification sheet that says (at least one segment of) the TSP has a 65 mph design speed in Westchester: https://i.imgur.com/xi5xsV9.png. That is, why design a 65 mph highway only to post it at a lower speed? Or maybe I misunderstand what design speed is. Thanks!

It's common practice to have a design speed higher than the posted limit by 5-10 MPH purely for the sake of having a factor of safety built in. Look at it this way: if your calculations say it's unsafe to drive 66 MPH, telling people it's okay to go 65 leaves no room for error.

Of course this is part of why driving 5-10 MPH over the posted speed limit so often feels perfectly safe - because speed limits are usually set deliberately conservatively.

That's why American speed limits are so dumb - they don't tell you at all what the actual speed limit is. They throw a random number out, say "we'll pull you over for either 5 or 15 over, depending on how broke we are" and don't actually tell you the maximum safe speed. If the limit was actually the limit - the fastest you can safely drive - and it was set at 65 (and this system was in effect nationwide), people would comply because they know what the limit means.

The design speed is not necessarily the safest you can drive. There is no one number that you can say is the maximum possible safe speed for all vehicles 24/7. There can be conditions where faster or slower than design speed might be safe due to weather. Different vehicles have different braking and traction, so a speed that is safe for one might not be for others. In some cases, with low accident rates, agencies have posted speed limits above the design speed.

[odditude]

also, keep in mind that it's good engineering practice (across ALL disciplines, whether it be traffic, structural, mechanical, electrical, aerospace, etc) to have a safety margin beyond the stated limits, to ensure that a single or minor flaw doesn't immediately result in functional failure.

[empirestate]

The overpass and ramps are now open (pursuant to an agreement with the town not to leave the school bus detour in place over the winter). It's not altogether finished, but all the parts seem to be in place and working. No exit signage to speak of yet.

[paul02474]

Apparently, the state accelerated the bridge project in order to permit Pudding Street traffic to cross the parkway over the winter.
https://news.hamlethub.com/somers/places/5503-pudding-street-bridge-reconstruction-project-finished-months-ahead-of-schedule

[Tom958]

The overpass and ramps are now open (pursuant to an agreement with the town not to leave the school bus detour in place over the winter). It's not altogether finished, but all the parts seem to be in place and working. No exit signage to speak of yet.

And it's already shown thusly on Google Maps.

[empirestate]

The overpass and ramps are now open (pursuant to an agreement with the town not to leave the school bus detour in place over the winter). It's not altogether finished, but all the parts seem to be in place and working. No exit signage to speak of yet.

And it's already shown thusly on Google Maps.

Yup, and you can clearly see in that hybrid image (and in the diagrams posted earlier in the thread) how the bridge abutments sit directly in the path of the former carriageways. It was intriguing to watch how they first cut away the rock for the SB exit ramp, then basically re-dumped it all a few feet to the left to fill in the old SB roadway!