"Impossible" highway improvement projects

[ZLoth]

Does anyone have a list of "impossible" highway improvement projects. These are existing roads that have badly gone over the design capacity and/or expected lifetime, and are in critical need of replacement, but because of funding and/or political reasons, will probably not be replaced until a catastrophic event occurs. I can think of two right off the top of my head...

First Example: Queens-Brooklyn Expressway (QBE) in New York City aka I-278. There are numerous YouTube videos documenting is wrong with the "Interstate", including the fact that it lacks shoulders and the lanes are a little bit narrower, thus not up to Interstate standards. The "triple cantilever" section was reduced from three lanes to two as a band-aid solution. There have been various proposals to fix this freeway including moving it underground, but the costs have caused this project to go nowhere.

Second Example: I-5 drawbridge between Portland, OR and Vancouver, WA. How old are these two pre-Interstate bridges? This is a clear example of where a replacement bridge should be higher for ship traffic, but the nearby Portland International Airport prevents that due to FAA regulars. There have been multiple proposals that have ended up dying because of cost or other factors.

[hbelkins]

I-64 widening between the Watterson Expressway (I-264) and I-65 in downtown Louisville. The Cochran Hill Tunnel is a major obstacle.

[Bruce]

Second Example: I-5 drawbridge between Portland, OR and Vancouver, WA. How old are these two pre-Interstate bridges? This is a clear example of where a replacement bridge should be higher for ship traffic, but the nearby Portland International Airport prevents that due to FAA regulars. There have been multiple proposals that have ended up dying because of cost or other factors.

There is an ongoing replacement project that is already pretty far along in planning. They're currently preparing the final EIS but with normal federal funding looking uncertain for the next few years there's no guarantee that they'll make the 2027 start and 2030 completion. The project is working off existing agreements that require a record of decision to be reached by September 2025 and, barring anything drastic, they should make that deadline.

[Bruce]

As for other impossible projects: building a freeway lid over I-5 in Downtown Seattle (or a tunnel for the whole thing). It's being studied but the costs will be enormous and funding just won't be there. It would be a massive improvement in quality-of-life for the tens of thousands who live within earshot of the freeway and would allow a chance to untangle some of the substandard ramp designs that haven't been changed since the 1960s.

[NE2]

Darien Gap
Paving Pennsylvania Avenue in gold
Lions Gate Bridge

[kurumi]

In roughly descending order of impossibility, Connecticut:
* CT 9, Middletown
* I-84 reroute/tunnel/etc, Hartford
* I-84 and CT 8, Waterbury
* I-84 and US 7, Danbury
* Merritt Parkway and US 7, Norwalk

Limited to projects that have active plans and alternatives (no CT 11, Super 7, I-384 extension, "one more lane bro" for I-95, etc.)

CT 9 has been annoying for a long time, but there's no strong consensus and no forcing function (a viaduct at end of life, etc.). The latest proposal has northbound CT 9 trucks headed for downtown Middletown to go up to CT 99 and U-turn 

The Hartford and Waterbury projects... the CT 8 Mixmaster rehabs have bought some time. Maybe the Aetna Viaduct will get the same treatment. But there's more of a sense from many parties that they'd rather not prop up the same harmful design.

Danbury has some pie-in-the-sky alternatives (as does Waterbury) but we may see some smaller improvements that take the pressure off.

The 7/15 interchange with traffic lights IMO has the highest chance of moving forward. It fixes an obsolete Main Ave. interchange and puts the idea of a Super 7 to rest, pleasing a few different factions.

[PColumbus73]

In South Carolina, completing I-526 will probably go nowhere. Charleston County officials can't seem to commit to county funds, and the state won't budge until the county does. Even if they downgrade it to a parkway or boulevard like some of their most recent proposals, the project probably won't go anywhere for a long time. It will essentially be a long bridge over the Stono River.

[TheStranger]

This came to mind when I was at the Skyscrapercity Philippines subforum a few days ago:

Full-out interchange reconstructions in Metro Manila - namely the 1968 era Balintawak Cloverleaf (NLEX/A. Bonifacio Avenue/EDSA) in Quezon City and the ca. 1976 Magallanes Interchange in Makati (SLEX/Osmena Highway/EDSA).  Both easily could be candidates for full out stacks, with the Magallanes Interchange in particular needing new southbound Skyway/Osmena flyovers to northbound EDSA (the old left-hand ramp from Osmena south to EDSA north closed in 2019).

Skyway passing over both junctions is useful in providing an alternate route, but that didn't address the poor ramp geometry and capacity at either interchange.

Balintawak on Google Maps:
https://www.google.com/maps/place/Balintawak+Cloverleaf+Park/@14.656881,120.9970431,16z/data=!3m1!4b1!4m6!3m5!1s0x3397b68f7e0516dd:0x5f3bc0103bce3959!8m2!3d14.6568758!4d120.999618!16s%2Fg%2F11hcxb7lpj?entry=ttu&g_ep=EgoyMDI1MDIxOS4xIKXMDSoASAFQAw%3D%3D

Magallanes Interchange on Google Maps:
https://www.google.com/maps/place/Magallanes+Interchange+Park/@14.5400792,121.0142167,17z/data=!3m1!4b1!4m6!3m5!1s0x3397c93c25903035:0xc0a97fce6a7c5f2b!8m2!3d14.540074!4d121.0167916!16s%2Fg%2F11g81j5jh2?entry=ttu&g_ep=EgoyMDI1MDIxOS4xIKXMDSoASAFQAw%3D%3D

Related: The Bay Area contingent on this forum have mentioned the 880/101 junction, a 1950s cloverleaf that has never been upgraded.
https://www.google.com/maps/@37.3658205,-121.9029535,16z?entry=ttu&g_ep=EgoyMDI1MDIxOS4xIKXMDSoASAFQAw%3D%3D

[JayhawkCO]

An interstate alternative to Glenwood Canyon.

[vdeane]

puts the idea of a Super 7 to rest

How is that idea not already at rest?  The freeway ends at an at-grade and there are plans to have it flow directly into two-lane US 7 north of there.

[LilianaUwU]

Plowing the snow in Québec City.

[Henry]

The Hypotenuse Expressway in Chicago...oh wait, that's not a real proposal? Well then, the Crosstown Expressway/Mid-City Transitway.

[Bobby5280]

In the case of the BQE in Brooklyn, I think the odds are at least 50/50 the whole thing could be torn down and turned into various surface streets. Obviously this would create one hell of a traffic bottleneck in Bay Ridge and force a lot of "thru" traffic onto the Belt Parkway. But with the replacement costs of the elevated viaduct going ever higher into not-feasible territory what the hell other choice does the state have? Digging a tunnel is an even more cost-prohibitive option. It's not just the cost of construction alone, it's the task of dodging around all the existing mess already under ground.

New York City has several other "impossible" improvement projects. So many of the super highways in the 5 boroughs have outdated design features, such as lack of shoulders and sub par ramp designs. Widening these highways and improving ramp geometry is likely impossible due to how densely packed existing development is next to the highways.

There is little if any feasible way of connecting I-495 in New Jersey with I-495 on Long Island. The only way I can see it being done is by deep bore drilling tunnels roughly 5 miles long to completely bypass under Manhattan as well as the Hudson and East Rivers. The existing Lincoln Tunnel and Queens-Midtown Tunnel would turn into exit stubs. There's no telling how many billions of dollars this would cost. Hell, the cost of just replacing those existing highway tunnels could break the bank.

[Gnutella]

1. Enlarging the Fort Pitt and Squirrel Hill Tunnels in Pittsburgh to fit six lanes of highway, so I-376 can be modernized and expanded to six lanes.

2. Modernizing the Schuylkill Expressway, expanding it to six or eight lanes from the Pennsylvania Turnpike to I-676, and six lanes from I-676 to I-95, and reconstructing it below grade with a lid through South Philadelphia.

Given that the Pennsylvania Turnpike Commission is now moving forward with a direct interchange at Breezewood, and PennDOT is about to reconfigure multiple interchanges on I-376 in Pittsburgh, maybe the two projects I mentioned aren't so "impossible" after all, though both would certainly be expensive, long-term projects.

[mgk920]

1. Enlarging the Fort Pitt and Squirrel Hill Tunnels in Pittsburgh to fit six lanes of highway, so I-376 can be modernized and expanded to six lanes.

2. Modernizing the Schuylkill Expressway, expanding it to six or eight lanes from the Pennsylvania Turnpike to I-676, and six lanes from I-676 to I-95, and reconstructing it below grade with a lid through South Philadelphia.

Given that the Pennsylvania Turnpike Commission is now moving forward with a direct interchange at Breezewood, and PennDOT is about to reconfigure multiple interchanges on I-376 in Pittsburgh, maybe the two projects I mentioned aren't so "impossible" after all, though both would certainly be expensive, long-term projects.

I'll agree on the 'impossible' direct I-70 connection at Breezewood throughout the second half of the 20th century and into the very early 21st century.  More recently, with the literal dying of the US 30 commercial district there, it is definitely now not so 'impossible'.

Mike

[PColumbus73]

In the case of the BQE in Brooklyn, I think the odds are at least 50/50 the whole thing could be torn down and turned into various surface streets. Obviously this would create one hell of a traffic bottleneck in Bay Ridge and force a lot of "thru" traffic onto the Belt Parkway. But with the replacement costs of the elevated viaduct going ever higher into not-feasible territory what the hell other choice does the state have? Digging a tunnel is an even more cost-prohibitive option. It's not just the cost of construction alone, it's the task of dodging around all the existing mess already under ground.

New York City has several other "impossible" improvement projects. So many of the super highways in the 5 boroughs have outdated design features, such as lack of shoulders and sub par ramp designs. Widening these highways and improving ramp geometry is likely impossible due to how densely packed existing development is next to the highways.

There is little if any feasible way of connecting I-495 in New Jersey with I-495 on Long Island. The only way I can see it being done is by deep bore drilling tunnels roughly 5 miles long to completely bypass under Manhattan as well as the Hudson and East Rivers. The existing Lincoln Tunnel and Queens-Midtown Tunnel would turn into exit stubs. There's no telling how many billions of dollars this would cost. Hell, the cost of just replacing those existing highway tunnels could break the bank.

I think in order to rebuild the BGE, they'd have to look at Tokyo for the above-ground portions and mix it with the Big Dig for the tunneled portions. Possibly even building it below interstate standards. If they wanted to rebuild it within the existing right-of-way AND bring it up to current standards, the City would have to accept reducing lanes to provide a shoulder. Then I would expect shoulder runners to be such a chronic issue that you might as well not have shoulders.

[kernals12]

I-95 in Fairfield County, Connecticut.

[epzik8]

Gotta say at least the western approach to the George Washington Bridge in Fort Lee.

[Gnutella]

1. Enlarging the Fort Pitt and Squirrel Hill Tunnels in Pittsburgh to fit six lanes of highway, so I-376 can be modernized and expanded to six lanes.

2. Modernizing the Schuylkill Expressway, expanding it to six or eight lanes from the Pennsylvania Turnpike to I-676, and six lanes from I-676 to I-95, and reconstructing it below grade with a lid through South Philadelphia.

Given that the Pennsylvania Turnpike Commission is now moving forward with a direct interchange at Breezewood, and PennDOT is about to reconfigure multiple interchanges on I-376 in Pittsburgh, maybe the two projects I mentioned aren't so "impossible" after all, though both would certainly be expensive, long-term projects.

I'll agree on the 'impossible' direct I-70 connection at Breezewood throughout the second half of the 20th century and into the very early 21st century.  More recently, with the literal dying of the US 30 commercial district there, it is definitely now not so 'impossible'.

Mike

When the Turnpike Commission builds the new direct interchange, Buc-ees should open in Breezewood. It'd be a win/win scenario for everybody. Those who don't want to stop won't have to stop, and the commercial drag will have something to offer those who do want to stop.

[Bobby5280]

I think in order to rebuild the BGE, they'd have to look at Tokyo for the above-ground portions and mix it with the Big Dig for the tunneled portions. Possibly even building it below interstate standards.

Not many segments of urban freeways or urban toll roads in Japan are built to US Interstate standards. Heck, even most of the rural super highways wouldn't meet US Interstate standards either. It's common for the highways to lack any shoulders. If the highway does have good outboard shoulders it almost always lacks any inner shoulders. Ramp geometry is another problem. Urban controlled access highways in Japan can have some pretty tight turns too. One thing that is impressive with Japan's highway network: they don't seem to have much trouble building tunnels. There is a LOT of them there.

Japan can get away with the deficiencies in its highway network due to the country having a very well established mass transit system. They have a famous high speed rail system. Japan also has a very complex passenger rail network. The biggest cities also have their own subways, light rail systems, etc. Bus and taxi service is available most places.

New York City has a great deal of its own mass transit options. I think re-building the BQE with a sub-standard design would be a waste of money. I have trouble seeing any approach could be feasible. A mix of elevated freeway and below grade tunneling would be especially difficult given the transitions between the two can't have anything steeper than a 6% grade. And any new highway tunnels in Brooklyn would have to be bored really deep under ground to dodge existing subway tunnels and a giant rat's nest of utilities.

[PColumbus73]

I believe most of Japan's expressways are operated by private, or semi-private/government corporations. However, I was thinking of how frequent multi-deck expressways are in Japanese cities. I doubt something like that would get built to replace the BQE, but assuming they wanted to fit modern design standards within the existing footprint, I don't see many options.

Keeping access to the bridges and tunnels into Manhattan might also force them to keep near to the existing alignment. NYC speed limits appear to max out at 50, so maybe they could design it to the lower speed limit while including shoulders. There wouldn't be much point to building a 70 MPH freeway if it's surrounded by 50 MPH freeways with no plans to upgrade a section to connect it to a more modern freeway, like the NJTP.

[I-55]

I-24 between I-440 and the I-65 north split probably won't ever be widened/modernized until bridges start falling down.

I-80/94 since both Indiana and Illinois canceled the Illiana and the only proposed solution to the Borman right now is flex lanes (aka surrendering to the problem. At least when ISTHA does them they're usually included with a mainline widening and not intended to be the solution for typical demand).

Almost any major project in Indiana outside of Indianapolis or SW Indiana. Already have seen multiple widenings on I-65 and I-70 get shortened due to budget constraints as funding will prioritize I-465's third round of widening in the last decade (82nd St to US 31) and Mid States Corridor (where the governor is from) before anything else can see full improvements.

[dvferyance]

I-64 widening between the Watterson Expressway (I-264) and I-65 in downtown Louisville. The Cochran Hill Tunnel is a major obstacle.

But why can't the widen everything else that isn't the tunnel?

[webny99]

I-64 widening between the Watterson Expressway (I-264) and I-65 in downtown Louisville. The Cochran Hill Tunnel is a major obstacle.

But why can't the widen everything else that isn't the tunnel?

Even if they could, there's no point because it would just create a bottleneck approaching the tunnel.

[mgk920]

I-64 widening between the Watterson Expressway (I-264) and I-65 in downtown Louisville. The Cochran Hill Tunnel is a major obstacle.

But why can't the widen everything else that isn't the tunnel?

Even if they could, there's no point because it would just create a bottleneck approaching the tunnel.

Yea, they'd have to ream out the tunnel to do it properly.

Mike