High-Volume Cloverleafs

[sparker]

In Northern CA, the most obvious outdated/underpowered cloverleaf is San Jose's own US 101/I-880, which still features a surface-street jaunt from SB 880 to NB (compass WNW at that point) 101.  But there are others:  I-80/I-780 in Vallejo, despite C/D roadways along I-80, still backs up into the main lanes.  Originally that was the north end of I-680; that route was detoured onto the then-CA 21 freeway (Benicia-Cordelia) back in 1974, and the renumbered I-780 didn't see a lot of traffic until dense suburban development occurred along its length starting in the late '80's; now, it's a typical Bay Area mess, and that spills over onto I-80.  Actually, I-680 hosts a number of now-packed cloverleaves; the I-580/I-680 Dublin interchange -- albeit improved some time ago with a direct SB 680-EB 580 ramp -- still has 3 remaining 25 mph loops, including the very heavily used WB 580-SB 680 one (part of the Central Valley-Silicon Valley commute corridor) -- major modification is long overdue.  And I-680/CA 4 remains, with minor changes, as it was when opened circa 1963-64, although IIRC there was a local bond issue in Contra Costa County a few years back specifically addressing funding for revamping of that interchange.  Finally -- I-5/I-80 (with silent CA 99 overlapping I-5) in the Natomas area north of central Sacramento -- a cloverleaf with CD lanes and a single direct (WB 80>SB 5) ramp deployed in "turbine" fashion.  It was adequate until about a decade ago, when suburban development north of town overwhelmed the design capacity -- again, overdue for reconfiguration.

Why didn't they complete the us 101/i-808 movement? because it would have made sense ?

The lore surrounding the construction of the interchange has it that the property where the direct 880S (then CA 17/I-680) to 101N ramp would have been was the site of a major appliance warehouse whose owner had strong political connections and didn't want to move his business (and who had threatened to fight eminent domain proceedings tooth & nail).  The Division of Highways figured that SB 17 traffic going to Sunnyvale or Mountain View, northward via US 101, would simply use SSR 9 (now CA 237) from Milpitas over to Sunnyvale in any case, and that a direct ramp wasn't worth the deployment trouble.  So it was decided to simply use a half-diamond ramp to the old highway, Bayshore Blvd., and then require a right turn and about three blocks' worth of street travel before the ramp to NB 101 was reached.  That would have been easy if not for the SP industrial spur parallel to Bayshore and crossing it about halfway between the SSR 17 offramp and the US 101 on-ramp; the tracks are still there but only sporadically used today, while back in the '60's it served several major warehouses and a lumber yard -- and trains regularly blocked the freeway-to-freeway movement.  The appliance warehouse is no more; the property is occupied by the regional Coca-Cola distributor (who isn't going anywhere either!). 

[silverback1065]

there are a lot of bad cloverleaves in california.  i-10 has some bizarre ones in LA, I call them squashed cloverleaves.

[Roadsguy]

There aren't very many high-volume cloverleafs in Pennsylvania. Probably the worst remaining complete cloverleaf is the I-283/PA 283 interchange near Harrisburg. Many of the other worst cloverleafs were modified relatively recently to no longer be complete cloverleafs, like I-376 Exit 60 west of Pittsburgh, PA 581/US 15 near Harrisburg, etc.

VDOT sure seems to have always loved cloverleafs, though, so much so that every interchange on I-295 on the north and east sides of Richmond between I-64 and VA 895 is either a full cloverleaf or mostly a cloverleaf (the I-95 interchange, for example). There are only three along the entire interstate that aren't any form of cloverleaf, nor intended to be one: VA 895, SR 618, and the southern end at I-95. Other suburban VA expressways in the DC and Norfolk area are no exception.

[jaehak]

Seoul has a murder's row of three horrible cloverleafs. The southernmost one is next to one of the busiest Costcos in the world. The middle one is pretty central Gangnam and near a major bus terminal, and the northernmost is right by the busiest bus terminal in the country, where frequent buses from most every large city in Korea are forced to cross 4 lanes of traffic to use the loop.

[silverback1065]

Why are South Korea's map colors so much darker than anywhere else on google maps?  I've always thought that was weird.  When you zoom out, you see this box where everything inside is darker, and everything else around it is the standard google maps colors.  anyone else notice this effect? https://www.google.com/maps/@35.4784402,129.2584031,7.21z

south korea appears to be the only place i've seen this affect happen.

[Buffaboy]

Buffalo, on the other hand...

I didn't even have to click on that to know what it is. There's so few cloverleafs in the area to begin with. That one in particular snarls the entire area.

[Chris19001]

My two least favorites in Southeast PA are:
PA309 at Tillman Blvd in Allentown (https://www.google.com/maps/@40.5897216,-75.5543378,531m/data=!3m1!1e3)
US422 at PA100 south of Pottstown (https://www.google.com/maps/@40.239606,-75.6595051,316m/data=!3m1!1e3)
Each is difficult to safely merge from and each has decent volumes of traffic.

[jakeroot]

Why are South Korea's map colors so much darker than anywhere else on google maps?  I've always thought that was weird.  When you zoom out, you see this box where everything inside is darker, and everything else around it is the standard google maps colors.  anyone else notice this effect? https://www.google.com/maps/@35.4784402,129.2584031,7.21z

south korea appears to be the only place i've seen this affect happen.

I believe the South Korean government requests that foreign mapping services minimise the level of detail for national security purposes.

[silverback1065]

Why are South Korea's map colors so much darker than anywhere else on google maps?  I've always thought that was weird.  When you zoom out, you see this box where everything inside is darker, and everything else around it is the standard google maps colors.  anyone else notice this effect? https://www.google.com/maps/@35.4784402,129.2584031,7.21z

south korea appears to be the only place i've seen this affect happen.

I believe the South Korean government requests that foreign mapping services minimise the level of detail for national security purposes.

ahh that makes sense, i thought my computer was broken!

[Beltway]

VDOT sure seems to have always loved cloverleafs, though, so much so that every interchange on I-295 on the north and east sides of Richmond between I-64 and VA 895 is either a full cloverleaf or mostly a cloverleaf (the I-95 interchange, for example). There are only three along the entire interstate that aren't any form of cloverleaf, nor intended to be one: VA 895, SR 618, and the southern end at I-95.

The I-295 cloverleafs are large and ample designs, the route was basically built in the "Interstate 3.0 era", with long auxiliary lanes between the loops.

The new VA-618 Meadowville Road interchange is built with space for future loop ramps which would make it a full cloverleaf.

[davewiecking]

Several on VA's I-495, which were rebuilt within the past 5 years:
Chain Bridge Rd; VA-123 (https://www.google.com/maps/@38.9212376,-77.2171877,733m/data=!3m1!1e3). South of that, the US-50 interchange (https://www.google.com/maps/@38.8656696,-77.2198958,802m/data=!3m1!1e3) is a cloverleaf at heart, with lots of CD lanes and braided ramps. Next is a standard Cloverleaf at VA-236 (Little River Turnpike). Along this stretch, VA-7 (Leesburg Pike) and VA-620 (Braddock Road) are 7 ramp Parclos with an Express Lane ramp thrown in.

Headed out I-66, VA-243 (Nutley Rd; https://www.google.com/maps/@38.8785809,-77.2672835,579m/data=!3m1!1e3) and VA-286 (Fairfax Co Pkwy) are each cloverleafs with CD lanes.

Along MD's I-95/495, the MD-414 (Silver Hill Rd) interchange (https://www.google.com/maps/@38.8087815,-76.9707032,803m/data=!3m1!1e3) is a full cloverleaf, as are MD-4 (Pennsylvania Ave) and the afore-mentioned BW Pkwy. On MD's I-495, MD-650 (New Hampshire Ave; https://www.google.com/maps/@39.0190248,-76.9759189,577m/data=!3m1!1e3) isn't a true cloverleaf, but the alternative for the NE corner loop ramp does manage to provide the worst aspect of a cloverleaf: entering traffic weaving with exiting traffic. 2 others along the top of the Beltway are close: MD-97 (Georgia Ave) and US-29 (Columbia Pike).

There's a cloverleaf at the heart of the US-50/BW Parkway interchange (https://www.google.com/maps/@38.9194096,-76.9323051,961m/data=!3m1!1e3), with ramps to MD-201 (Kenilworth Ave) added. I-95 has cloverleafs at MD-212 (with a northbound CD lane) and MD-216; there are a few along the BW Pkwy/MD-295.

These are all close enough to the DC/Baltimore metropolitan area that they certainly count as "High-Volume".

I-70/I-81 (https://www.google.com/maps/@39.6167615,-77.7844509,1348m/data=!3m1!1e3) is a high volume cloverleaf with full CD lanes. A few other cloverleafs are in Frederick or elsewhere along I-70, but I'm not sure if they'd count as 'High-Volume".

[jakeroot]

As mentioned in the OP, Minneapolis seems to have a ton of cloverleafs (almost every interchange). I'm not sure if any of them are over capacity, but I would guess at least a few.

I remember when I flew into Minneapolis last year, I was staggered by all of the cloverleafs I could see out the window.

[MNHighwayMan]

As mentioned in the OP, Minneapolis seems to have a ton of cloverleafs (almost every interchange). I'm not sure if any of them are over capacity, but I would guess at least a few.

I remember when I flew into Minneapolis last year, I was staggered by all of the cloverleafs I could see out the window.

I-35W and I-494 is by far the worst interchange in the state. No question. Trying to go from NB I-35W to WB I-494 is a nightmare all day, every day, and sadly, there's no indication it will be fixed in the immediate future. Most proposed fixes are just too expensive and/or lack the political will to enact.

I-35W and I-694 is also rather terrible, but its awfulness is lessened by the existence of the US-10 shortcut to the northeast.

And... yeah. There's lots of others, and they all vary from "this is okay" to "ugh..." I'm not sure how the design became so popular in the Twin Cities.

[Beltway]

CD roadways are a way for high-volume cloverleaf interchanges to work quite well.  The weaving takes place on the CD roadway which has lower speeds and lower volumes than the freeway mainline roadway.

[per mention of I-495/US-50 and I-66/VA-243 interchanges]

[triplemultiplex]

I'm not sure how the design became so popular in the Twin Cities.

Well, they're cheaper than ones with nice flyovers, so you can build more system interchanges for the same price?

[froggie]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

[jaehak]

Why are South Korea's map colors so much darker than anywhere else on google maps?  I've always thought that was weird.  When you zoom out, you see this box where everything inside is darker, and everything else around it is the standard google maps colors.  anyone else notice this effect? https://www.google.com/maps/@35.4784402,129.2584031,7.21z

south korea appears to be the only place i've seen this affect happen.

I believe the South Korean government requests that foreign mapping services minimise the level of detail for national security purposes.

This is true, at least on paper. Google Maps is really defanged here, and a lot of features (like street view) are not available. The claim is for security reasons, but really it's more protectionism. GSV was more or less complete here when the government decided to kick out google and use essentially the same tech for domestic mapping services. Buses and subway lines work to some degree on google maps in Seoul, but it's mainly useless in other parts of the country. The local KakaoMap app is actually pretty cool and shows street view for mountain trails and subway stations, but the downside (at least for us expats) is that you can only search in Korean, and my Korean typing skills suck.

[cl94]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

Which is probably a reason cloverleafs and similar designs are so common in the Northeast still. I'd be willing to bet that most of the damage to bridges in these parts comes from salt, too.

[silverback1065]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

Which is probably a reason cloverleafs and similar designs are so common in the Northeast still. I'd be willing to bet that most of the damage to bridges in these parts comes from salt, too.

what the hell does salt have to do with it?  they salt cloverleaves too.

[cl94]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

Which is probably a reason cloverleafs and similar designs are so common in the Northeast still. I'd be willing to bet that most of the damage to bridges in these parts comes from salt, too.

what the hell does salt have to do with it?  they salt cloverleaves too.

Number of bridges. Temperature of bridge decks changes faster than the temperature of pavement on solid ground, so freezing is more of a concern.

[jakeroot]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

Which is probably a reason cloverleafs and similar designs are so common in the Northeast still. I'd be willing to bet that most of the damage to bridges in these parts comes from salt, too.

what the hell does salt have to do with it?  they salt cloverleaves too.

Number of bridges. Temperature of bridge decks changes faster than the temperature of pavement on solid ground, so freezing is more of a concern.

Wouldn't it be possible to install some sort of in-ground sprinkler or heating tube system on overpasses so that constantly salting them wouldn't be necessary? I seem to recall this being a thing in Japan, but I'm not sure the tech has been utilised in the US.

[cl94]

Also concerns about the level of salt and sand necessary to keep flyovers clear in the winter in a state where they already spend a large part of their budget on winter snow removal.

Which is probably a reason cloverleafs and similar designs are so common in the Northeast still. I'd be willing to bet that most of the damage to bridges in these parts comes from salt, too.

what the hell does salt have to do with it?  they salt cloverleaves too.

Number of bridges. Temperature of bridge decks changes faster than the temperature of pavement on solid ground, so freezing is more of a concern.

Wouldn't it be possible to install some sort of in-ground sprinkler or heating tube system on overpasses so that constantly salting them wouldn't be necessary? I seem to recall this being a thing in Japan, but I'm not sure the tech has been utilised in the US.

Has been done in a few places where icing has presented significant issues, but it is not common due to cost.

[froggie]

what the hell does salt have to do with it?  they salt cloverleaves too.

As cl94 noted, bridges freeze faster than roadways because you get airflow underneath the bridge deck.  As a result, it takes a bit more salt to clear a bridge than it does an adjacent roadway.  Furthermore, salt is corrosive on bridges and their decks, not to mention adjacent land come spring thaw.

Wouldn't it be possible to install some sort of in-ground sprinkler or heating tube system on overpasses so that constantly salting them wouldn't be necessary? I seem to recall this being a thing in Japan, but I'm not sure the tech has been utilised in the US.

The new I-35W bridge in Minneapolis sort of has a similar type anti-icing system.  But the technology hasn't matured in the U.S. and would be expensive to retrofit.

[mrcmc888]

I-70 at I-81, Hagerstown, MD.

Traffic going to Baltimore/Philadelphia from the Great Lakes collides with traffic going to Florida from the Northeast and it's all forced onto one outdated cloverleaf.  This one frequently causes delays during rush hours.

https://www.google.com/maps/@39.6166939,-77.7883613,16z?hl=en&authuser=0

I-295 and I-195 in Trenton, NJ

https://www.google.com/maps/@40.1868096,-74.7161359,15z?hl=en&authuser=0

[jakeroot]

Wouldn't it be possible to install some sort of in-ground sprinkler or heating tube system on overpasses so that constantly salting them wouldn't be necessary? I seem to recall this being a thing in Japan, but I'm not sure the tech has been utilised in the US.

The new I-35W bridge in Minneapolis sort of has a similar type anti-icing system.  But the technology hasn't matured in the U.S. and would be expensive to retrofit.

I can certainly see why old bridges haven't been retrofitted. That's a PITA and very disruptive. But on new overpasses, I think it would more cost-effective long term given salt's corrosive nature. I guess my hope is that MnDOT will start using (and pioneering) this technology more often. After all, they can't rely on cloverleafs forever.

EDIT: I just read that the original bridge had a de-icing system that might have contributed to corrosion. Is this true? Was this old tech?