Most Popular Interchange Trend by Decade

[Georgia Guardrail]

It is fascinating to see the evolution of freeway interchanges over the decades.  Excluding regular diamond interchanges, here is my list of what seems to be the most popular types of interchanges by decade. 

Any additions or revisions you would add?

Interchanges of Freeways and Non Freeways
Cloverleafs - 1940s thru 1960s
SPUIs - late 1970s thru mid 1990s
Diverging Diamonds - early 2010s to the present

Interchanges between Freeways
Cloverleafs - 1940s thru mid 1970s
Windmill - mid 1970s thru mid 1980s
Stacked Flyovers - late 1980s to present

My guess is that they used cloverleafs a lot initially because cars didn't accelerate as fast as they do today so not as much weave space at the merges was required.  Plus they had more room to build them than today because there was more space available then with less building around.

[kphoger]

Cloverleaf?  Why?  Because there was less traffic back then.  And because weaving wasn't the known issue then that it is now.

And what else had even been invented yet?

[vdeane]

Wouldn't slower accelerating cars make weaving more of an issue, not less?  Merging is more complicated with a big speed disparity, after all.  kphoger's reasoning re:cloverleafs makes more sense to me.

[lepidopteran]

Between turnpikes/toll roads and anything else, a double trumpet.  This would apply to the heyday of toll-road building, probably through the 1960s. I've often said that sometimes these were built even when a trumpet was not really needed for the non-freeway side.

Does not apply to toll roads that used a barrier system from the start.

[ran4sh]

With barrier tolls, the "butterfly" interchange was common, to allow both exiting and entering traffic to go through the same toll booth

[kurumi]

There may also be a transition between directional 3-way and semi-directional 3-way system interchanges (that is, left exit/entrance on the main route or not).

In Connecticut, at least (opening dates within a year or so, but plans date back earlier):

directional:
I-84 and US 7 (1961)
I-95, CT 349 (1966)
I-84, CT 72 (1970, 1975)
I-91/291 (1973, but construction halted)
CT 9/72 (1978 -- as CT 72 and SR 506)

semi-directional:
I-84/691 (1987)
I-84/384 (1989)
I-84/291 (1994)
I-91, CT 20 (1994)

[Henry]

For many years, the Circle Interchange (now Jane Byrne) was the only one of its kind, but now there are new interchanges that use this design, such as I-85 at I-485 north of Charlotte and I-295 at FL 202 east of Jacksonville. While stacks are great in their own right, I absolutely love the turbine because it functions like a stack, without all the extra levels.

[epzik8]

Diverging diamonds and single-point urban interchanges are all the rage right now...

[CtrlAltDel]

For many years, the Circle Interchange (now Jane Byrne) was the only one of its kind, but now there are new interchanges that use this design, such as I-85 at I-85 north of Charlotte and I-295 at FL 202 east of Jacksonville. While stacks are great in their own right, I absolutely love the turbine because it functions like a stack, without all the extra levels.

There's another one at I-4 and I-75, which would be one of my favorites, if it weren't for a nearby landmark.

[Scott5114]

I tend to associate SPUIs more with the 2000s, since during that decade it seemed like they were the king of the freeway-to-surface interchanges. (Oklahoma didn't get its first SPUIs until the tail end of the 2000s.)

[Georgia Guardrail]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

[ilpt4u]

How about Freeway "T"/3-way Interchanges?

Is there a timeline preference for a Trumpet vs the 3-level Y/T Stack Interchange?

[Henry]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

You probably meant to say dumbbells, but roundabout diamonds is just as good.

[mgk920]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

You probably meant to say dumbbells, but roundabout diamonds is just as good.

I've always heard them being referred to as 'Dogbone' roundabouts.

Mike

[freebrickproductions]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

You probably meant to say dumbbells, but roundabout diamonds is just as good.

I've always heard them being referred to as 'Dogbone' roundabouts.

Mike

I thought those two were slightly different?

[Big John]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

You probably meant to say dumbbells, but roundabout diamonds is just as good.

I've always heard them being referred to as 'Dogbone' roundabouts.

Mike

I thought those two were slightly different?

Yes, a dumbell has a full circle on both ends while a dogbone omits the inside portion on both ends as it is lightly used as it can only be used to make a U-turn.

[roadman65]

I wonder if NJ will ever build a DDI or Dogbone? They seem to be the only state that don't want to accept modern design and still even keeping a cloverleaf at the Garden State Parkway/ NJ 37 intersection where other states would convert to a SPUI or Parclo.

Most likely it's because NJDOT likes it's left turn free arterials which a SPUI would violate, but a Parclo could still work having the exits on the right to match the jug handles.

[epzik8]

Forgot to add the roundabout diamonds.  Along with diverging diamonds, those seem increasingly more popular as well from the mid 2010s to the present.

You probably meant to say dumbbells, but roundabout diamonds is just as good.

Whatever they're called, there can never be enough of them in my eyes (even if some find them tricky to navigate...)