When did the cloverleaf fall out of fashion?

[cbeach40]

Good, it's about time we get rid of those weaving nightmares. Don't know why we used them in the first place.

Provides complete free-flow movement with only one structure. The impact of weaving wasn't well understood in the early years of freeways.
Of course, any built in the last 50 years has no excuse.

[1995hoo]

My impression is that very few new cloverleafs were built after the mid 1960s.

I would add a caveat: very few new interstate to interstate cloverleafs, especially in urban areas.

As a follow-up, I can think of various freeway-to-freeway ones that have been modified due to congestion caused by the weaving problem. The two that most readily come to mind are the Capital Beltway and US-50 (unsigned I-595) in Maryland (only one loop ramp remains there) and the I-77/I-40 interchange in Statesville (three loops remain). I'd have to think harder to come up with other ones; these are just the two that immediately come to mind when I consider the issue.

[jeffandnicole]

Good, it's about time we get rid of those weaving nightmares. Don't know why we used them in the first place.

Provides complete free-flow movement with only one structure. The impact of weaving wasn't well understood in the early years of freeways.
Of course, any built in the last 50 years has no excuse.

But there's other issues to consider.  Weaving is just one of many variables when constructing an interchange.

[mgk920]

There are a few remaining interstate highway cloverleaves left here in Wisconsin, one that I know is being actively studied for elimination (I-43/WI 100/Drown Deer Rd in northern Milwaukee County) and one elimination is under construction (I-39/90/I-43/WI 81 in Beloit).  One was rebuilt a few years ago with new C/D lanes on the interstate side (I-39/90/94/US 151/Washington Ave in Madison), one that I know of was built with C/D lanes on the interstate side (I-43/WI 23 in Sheboygan), one just makes be scratch my head, but has C/D lanes (I-94/US 53 in Eau Claire) and one non-interstate freeway to freeway one was built new since 2000 (US 53/WI 29 between Eau Claire and Chippewa Falls).  There is also an interstate one with C/D lanes on the non-interstate side (I-43/US 12 in Elkhorn).

Mike

[kphoger]

So does anyone have a real answer to the question from the OP?  When did agencies start moving cloverleaf interchanges down the list?

[formulanone]

So does anyone have a real answer to the question from the OP?  When did agencies start moving cloverleaf interchanges down the list?

1983½ model year

[GaryV]

The I-94/I-69 interchange was built as a full cloverleaf, but with C/D ramps.  This was about 1967.

[briantroutman]

So does anyone have a real answer to the question from the OP?  When did agencies start moving cloverleaf interchanges down the list?

It would vary by state DOT, but my rough guess would be "late '70s"  based on various facilities I'm familiar with. The full eight-ramp cloverleaf, as used for freeway-freeway connections, was still quite popular through the '60s, spanning most of the original Interstate construction period, and it continued to be rolled out into the mid "˜70s, mostly on freeways that had been designed and were in progress since the previous decade.

[1995hoo]

I'd be mildly interested in seeing some sort of count of how many freeway-to-freeway cloverleaf interchanges each state has, potentially further broken out into with and without C/D roadways, and a count of how many of each category each state used to have that have since been modified. But I have no idea where to find that information nor the motivation to try to compile it.

My sense is that some states have been more likely than others to build that style of interchange; for example, I-26 in South Carolina readily comes to mind as one that used to have three non-C/D road cloverleafs with other Interstates (I-95, I-20, and I-85; the I-85 one still exists in the same form, but it's now an interchange with I-85 Business due to the road being moved to a new alignment).

[webny99]

I have no idea where to find that information

googlemaps.com?

nor the motivation to try to compile it.

A journey of a thousand miles begins with a single step.
On a more serious note, maybe a few of us will be willing to compile it for our own states. There's really not that many when you limit it to freeway-freeway examples only. I'll do New York, excluding the NYC area:

I-90/NY 33
I-81/I-481/NY 481
I-86/NY 201
I-787/NY 7
I-84/NY 17
I-81-86/NY 7: Used to be a full cloverleaf. It's currently under construction and will basically be a diamond with a NB to WB loop when finished.
NY 8-12/NY 49: Currently has 2 flyovers, but it may have been a full cloverleaf in the past. I'm not sure.

I stand to be corrected, but I believe that's an exhaustive list. None of them have C/D roads. NY does not seem to believe in those. NY is also unique in that our most significant 2di's (I-90 and I-87) are mostly tolled, so most interchanges are trumpets, or double-trumpets in the case of freeway-freeway junctions. Of course, this list would quadruple (or more) in length if we included examples involving one or more non-freeways.

[1995hoo]

I have no idea where to find that information

googlemaps.com?

Aside from the obvious practical issue of the massive amount of time that would take, it doesn't help with historical data. For example, the interchange of the Capital Beltway and US-50 that I mentioned earlier would be a good example–Google Maps shows the current configuration and not the old cloverleaf.

....

On a more serious note, maybe a few of us will be willing to compile it for our own states. There's really not that many when you limit it to freeway-freeway examples only. I'll do New York, excluding the NYC area:

I-90/NY 33
I-81/I-481/NY 481
I-86/NY 201
I-787/NY 7
I-84/NY 17
I-81-86/NY 7: Used to be a full cloverleaf. It's currently under construction and will basically be a diamond with a NB to WB loop when finished.
NY 8-12/NY 49: Currently has 2 flyovers, but it may have been a full cloverleaf in the past. I'm not sure.

I stand to be corrected, but I believe that's an exhaustive list. None of them have C/D roads. NY does not seem to believe in those. NY is also unique in that our most significant 2di's (I-90 and I-87) are mostly tolled, so most interchanges are trumpets, or double-trumpets in the case of freeway-freeway junctions. Of course, this list would quadruple (or more) in length if we included examples involving one or more non-freeways.

The issue noted in boldface definitely occurred to me as an issue that prevails in several places in the Northeast.

[hbelkins]

Kentucky cloverleafs, full freeway to full freeway:

I-64/I-265 (will be replaced)
I-71/I-265 (will be replaced)
I-65/I-165-Natcher Parkway (has CD lanes on I-65)
I-65/WK Parkway-US 31W-KY 61 (has CD lanes on I-65)
I-165/WK Parkway

Replaced as part of the I-69 construction:

I-24/Purchase Parkway
WK Parkway/Pennyrile Parkway

There are some cloverleafs on various interstates in urban areas, but they are not freeway-to-freeway junctions.

[MikeTheActuary]

I think in (mostly urban) places where there's a lot of exits spaced out every mile (or less), it's understandable to not hang out there if you're at least doing the speed limit, if there's several lanes of travel.

In Connecticut, where it is common for freeways to have high traffic volumes, for exits to be spaced less than a mile apart, and for acceleration and deceleration lanes to be too short for the de facto speeds, the middle lane is the lane with the most stable, consistent speeds.

Attempting to keep to the right lane leads to frequent lane changes (if traffic is light enough accommodate the change), or frequent speed changes due to exiting traffic slowing down, and entering traffic merging in at less than the prevailing speeds.

The situation is such that driving schools in the state frequently teach the middle lane as being the "thru lane", with the left lane reserved for passing, and the right lane reserved for extended entry/exit movements or vehicles unable to keep up with highway speeds.

[jmacswimmer]

Here's my attempt at Maryland's freeway-to-freeway cloverleafs:

I-70/I-81 (with full CD lanes on both routes)
I-95-495/MD 4 (4's freeway segment currently stops a mile and half to the southeast, but is planned to eventually continue all the way to the beltway)
I-95-495/MD 295
US 50/MD 201/MD 295 (there's a lot of stuff happening here, probably easier to look for yourself than me attempt to explain)
I-95/MD 200 (with full CD lanes on I-95, plus an additional express flyover ramp for the EB-NB movement)
US 29/MD 32 (32 East has a double-line-separated CD lane)
MD 295/MD 32
MD 295/MD 100 (100 East has a double-line-separated CD lane)
I-695/MD 295

Also including some 3/4-cloverleafs:
I-95-495/MD 5
I-70/US 29
I-695/I-83 South
I-95/MD 100
I-195/MD 295

Finally, also worth noting that every interchange on I-95 "between the beltways" is either a full cloverleaf or partial cloverleaf, with the exception of exits 32 & 46.

[webny99]

I have no idea where to find that information

googlemaps.com?

Aside from the obvious practical issue of the massive amount of time that would take, it doesn't help with historical data. For example, the interchange of the Capital Beltway and US-50 that I mentioned earlier would be a good example–Google Maps shows the current configuration and not the old cloverleaf.

I wasn't really being serious and almost added an emoji to indicate such, but your point about the historical data is a good one. Hadn't thought of that.

NY is also unique in that our most significant 2di's (I-90 and I-87) are mostly tolled, so most interchanges are trumpets, or double-trumpets in the case of freeway-freeway junctions. Of course, this list would quadruple (or more) in length if we included examples involving one or more non-freeways.

The issue noted in boldface definitely occurred to me as an issue that prevails in several places in the Northeast.

I wasn't thinking of it is an issue per se, except that it just means we tend to have fewer cloverleaf interchanges. And, in the case of New York, there's so few that the state has never really had a reason to consider improvements, such as C/D roads, that have become commonplace in other states.

[texaskdog]

Minneapolis & Saint Paul loved them.  Here in Austin I know there are a couple (183 & 71 which may disappear in current reconstruction; Mopac & 35th kind of; I'd have to think but there are probably a couple more).  generally we have flyovers or you have to exit, take a left, and get on the next highway

[1995hoo]

NY is also unique in that our most significant 2di's (I-90 and I-87) are mostly tolled, so most interchanges are trumpets, or double-trumpets in the case of freeway-freeway junctions. Of course, this list would quadruple (or more) in length if we included examples involving one or more non-freeways.

The issue noted in boldface definitely occurred to me as an issue that prevails in several places in the Northeast.

I wasn't thinking of it is an issue per se, except that it just means we tend to have fewer cloverleaf interchanges. And, in the case of New York, there's so few that the state has never really had a reason to consider improvements, such as C/D roads, that have become commonplace in other states.

I didn't mean to use the word "issue" in the sense of "problematic," but I can see how my comment might have been interpreted that way. I just meant that in the Northeast I think there is a relatively high percentage of toll roads or former toll roads, especially "ticket system" toll roads, that would place a natural limit on the use of cloverleafs that might not be an issue in states with fewer toll roads or higher percentages of free Interstate-grade highways. (Certainly there are toll roads that use the barrier toll system that do have cloverleafs; the Powhite Parkway, VA-76, near Richmond comes to mind, as it has a freeway-to-freeway cloverleaf with VA-288 that has C/D roads only on VA-288, although I suppose that interchange is to the west of the last toll barrier.)

[ftballfan]

US-131/M-6 was built as a cloverleaf (with C/D roads) in 2004

[vdeane]

I have no idea where to find that information

googlemaps.com?

nor the motivation to try to compile it.

A journey of a thousand miles begins with a single step.
On a more serious note, maybe a few of us will be willing to compile it for our own states. There's really not that many when you limit it to freeway-freeway examples only. I'll do New York, excluding the NYC area:

I-90/NY 33
I-81/I-481/NY 481
I-86/NY 201
I-787/NY 7
I-84/NY 17
I-81-86/NY 7: Used to be a full cloverleaf. It's currently under construction and will basically be a diamond with a NB to WB loop when finished.
NY 8-12/NY 49: Currently has 2 flyovers, but it may have been a full cloverleaf in the past. I'm not sure.

I stand to be corrected, but I believe that's an exhaustive list. None of them have C/D roads. NY does not seem to believe in those. NY is also unique in that our most significant 2di's (I-90 and I-87) are mostly tolled, so most interchanges are trumpets, or double-trumpets in the case of freeway-freeway junctions. Of course, this list would quadruple (or more) in length if we included examples involving one or more non-freeways.

I-787/NY 7 has always existed in its current form with the WB/SB flyover.

The I-87/NY 17/NY 7 interchange has already been reconfigured.

[webny99]

The I-87/NY 17/NY 7 interchange has already been reconfigured.

OK, I wasn't aware of the current project status. It's been ongoing for so long that I had my doubts that construction had fully wrapped.

[D-Dey65]

My impression is that very few new cloverleafs were built after the mid 1960s.

Florida used them in bunches for throughout their interstate binge of the 1970s and early-1980s.  Lots of fresh right-of-way. Loads of parclos also remain...yay for 25 mph traffic trying to merge in with overzealous right-lane passers!

One of the most recent ones I know about is US 27 and FL 50 in Clermont. The southern portion of it really needs to be fixed though.

[froggie]

Vermont is easy in this regard...we only have three freeway-to-freeway interchanges to begin with.  And none of them are traditional cloverleaf interchanges.

[hbelkins]

Here's my attempt at Maryland's freeway-to-freeway cloverleafs:

I-70/I-81 (with full CD lanes on both routes)

And it still has short/no merge areas.

[Ned Weasel]

And it still has short/no merge areas.

Here's one with neither C-D lanes nor auxiliary lanes: https://goo.gl/maps/sRqTJASPN2sRt8XV7

But it has stop signs at the ends of the ramps!

[wriddle082]

Tennessee has three of these:

I-81 and I-26 (when built in the mid-70's, I-26 was still US 23)

I-24 and TN 155 Briley Pkwy in NW Nashville (I-24 has C/D lanes)

I-40 and I-269/TN 385 in Arlington (I-40 has C/D lanes), which is the newest of the bunch, built in the late 90's.