Flyswatter Interchanges

[Troubleshooter]

I call an interchange a flyswatter interchange when it looks like some designers got tired of the problem, threw some drawings of interchange parts on a map, and then went SPLAT with a flyswatter.

Here are some of the worst:

1. Beaverdam OH: I-75 and US-30 come together with two different interchanges that connect to a county road that used to be US-30.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=beaverdam+OH&sll=41.882626,-87.645772&sspn=0.002249,0.004136&ie=UTF8&hq=&hnear=Beaverdam,+Allen,+Ohio&ll=40.830762,-83.974771&spn=0.036563,0.066175&t=k&z=14

2. Wooster OH: This was staged construction, but huh?

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&ll=40.796333,-81.912775&spn=0.018161,0.033088&t=k&z=15

3. Columbia NJ:

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&ll=40.925414,-75.090158&spn=0.009063,0.024719&t=k&z=16

4. North Caldwell NJ: Complete, unless you exit from I-80 eastbound. Then you have to go to the next interchange to turn around.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=40.895835,-74.244404&sspn=0.018134,0.033088&ie=UTF8&ll=40.895835,-74.244404&spn=0.018134,0.033088&t=k&z=15

5. Passaic NJ: More turns you can't make than you can.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Passaic+NJ&sll=41.882626,-87.645772&sspn=0.002233,0.004136&ie=UTF8&hq=&hnear=Passaic,+New+Jersey&ll=40.879776,-74.165311&spn=0.018138,0.033088&t=k&z=15

6. New London CT: If anyone can explain this, I'm listening.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=New+London,+CT&sll=40.879776,-74.165311&sspn=0.018138,0.033088&ie=UTF8&hq=&hnear=New+London,+Connecticut&ll=41.366213,-72.104945&spn=0.018004,0.033088&t=k&z=15

7. Pook's Hill MD: Can't make many turns

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Pook%27s+Hill+MD&sll=41.366632,-72.104945&sspn=0.017199,0.033088&ie=UTF8&hq=&hnear=Pooks+Hill,+Rockville,+Montgomery,+Maryland&ll=39.019234,-77.103767&spn=0.009319,0.016544&t=k&z=16

8: The Birmingham AL "Hubris" Interchange: I call it this because someone in the 1960s made a cartoon of it. The ramps were in accurate places, but the road signs had such fanciful destinations as "Hubris", "Finsterwood", and "Dimpleville" for the exits. There were hundreds of useless signs. The article was about the overuse and bad usage of road signs.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Birmingham+AL&sll=39.019234,-77.103767&sspn=0.009319,0.016544&ie=UTF8&hq=&hnear=Birmingham,+Jefferson,+Alabama&ll=33.521344,-86.799374&spn=0.01,0.016544&t=k&z=16

[Truvelo]

1. Beaverdam OH: I-75 and US-30 come together with two different interchanges that connect to a county road that used to be US-30.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=beaverdam+OH&sll=41.882626,-87.645772&sspn=0.002249,0.004136&ie=UTF8&hq=&hnear=Beaverdam,+Allen,+Ohio&ll=40.830762,-83.974771&spn=0.036563,0.066175&t=k&z=14

That is diabolical. Why go to the effect of building a large freeflow interchange on US-30 when it doesn't even connect to I-75. It reminds me of Breezewood and I see there's already a growing cluster of gas stations and fast food restaurants ready to take money from turning traffic.

Something else I noticed in the area is further east at Williamstown where US-68 crosses the old US-30 alignment the bridge over US-68 has been removed. It seems the bypass around Williamstown being being reduced to two lanes and the bridge replaced with an at-grade junction.

[froggie]

1. Beaverdam OH: I-75 and US-30 come together with two different interchanges that connect to a county road that used to be US-30.

With this one, one should consider that the railroad running along the west side of I-75 is a major complication for any potential direct 75/30 connection.

6. New London CT: If anyone can explain this, I'm listening.

This one's actually simple.  You have a local access interchange, and immediately adjacent to it is a 3/4 interchange shoehorned in for a cancelled freeway.

7. Pook's Hill MD: Can't make many turns

Technically considered part of Bethesda.

And for this one, you have to look at history.  Rockville Pike is the original US 240.  I-270 was built first with US 240 rerouted onto it.  Then the Beltway was built to the east.  Then finally the Beltway to the west.  But since this area was already somewhat developed by the time the Beltway was built, both it, some of the interchange ramps, and Metro's Red Line had to be shoehorned into the available right-of-way, nevermind that you have Rock Creek Park adjacent to the eastern third of the interchange.

8: The Birmingham AL "Hubris" Interchange:

This one may look weird, but consider the loop ramp near the bottom has long been closed to traffic.  So the remaining ramps effectively serve as a half-interchange to/from the south.

[deathtopumpkins]

If you look around at the surroundings a lot of those interchanges make perfect sense.

For example, #5: The GSP SB to 19 NB and 19 SB to GSP NB connections are facilitated by I-80 to the north.
And #7: Why would you want to use any of the missing connections there? All of the freeway-freeway connections are facilitated by the other I-270 spur.

And, excepting the US 30 / I-75 example, I daresay most of those interchanges are partials or funky configurations because that is all that either traffic volumes warrant or space and budget allow for.

[njroadhorse]

3. Columbia, NJ

I don't think there's any way avoiding the complexity of this one. Both roads (US 46 and NJ 94) intersect at weird angles with Interstate 80 and there's a truck stop we have to account for here.  Without the current configuration, the town of Columbia would've been cut off.

4. North Caldwell, NJ

This one could've been fine as a stack or cloverleaf, but unfortunately US 46 runs too close to the interchange for that to work.

[Hot Rod Hootenanny]

Your two examples along US 30 in Ohio are relatively tame compared to this interchange complex west of Marysville for US 33/36, Oh 4/245
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&t=k&ll=40.2398,-83.402796&spn=0.015757,0.038495&z=15

[Revive 755]

1. Beaverdam OH: I-75 and US-30 come together with two different interchanges that connect to a county road that used to be US-30.

With this one, one should consider that the railroad running along the west side of I-75 is a major complication for any potential direct 75/30 connection.

Looks like plenty of space between the two local access interchanges on I-75 to at least add WB-SB and NB-EB ramps.  Back when ODOT was deciding on an alignment for US 30 through that area, they should have considered the difficulty of adding a full or partial service interchange as part of the alignment selection - Illinois at least used this to pick where I-255 would cross I-270 near Edwardsville.  ODOT should have had US 30 cross I-75 away from the E-W section of I-75 near Beaver Dam.

4. North Caldwell NJ: Complete, unless you exit from I-80 eastbound. Then you have to go to the next interchange to turn around.

Now that whole area is just strange with the near-freeway grade US 46 running that close to I-80.  Had I designed it, I might have left out access to/from I-80 to US 46 at the NJ 23 interchange, and had more local access to I-80 with a set of one-way outer roads for I-80.

My nominations for the Flyswatter Interchange Award:

* The I-83/I-283/US 322 interchange near Harrisburg, PA:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=40.895835,-74.244404&sspn=0.018134,0.033088&ie=UTF8&t=k&ll=40.25323,-76.805871&spn=0.012381,0.041199&z=16]http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=40.895835,-74.244404&sspn=0.018134,0.033088&ie=UTF8&ll=40.895835,-74.244404&spn=0.018134,0.033088&t=k&z=15[url][/quote]Now%20that%20whole%20area%20is%20just%20strange%20with%20the%20near-freeway%20grade%20US%2046%20running%20that%20close%20to%20I-80.%20 Had%20I%20designed%20it,%20I%20might%20have%20left%20out%20access%20to/from%20I-80%20to%20US%2046%20at%20the%20NJ%2023%20interchange,%20and%20had%20more%20local%20access%20to%20I-80%20with%20a%20set%20of%20one-way%20outer%20roads%20for%20I-80.My%20nominations%20for%20the%20Flyswatter%20Interchange%20Award:*%20The%20I-83/I-283/US%20322%20interchange%20near%20Harrisburg,%20PA:[url]http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=40.895835,-74.244404&sspn=0.018134,0.033088&ie=UTF8&t=k&ll=40.25323,-76.805871&spn=0.012381,0.041199&z=16

* The Tri-Level Interchange (I-55-70 with I-64 and IL 3) in East St. Louis, IL:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=40.895835,-74.244404&sspn=0.018134,0.033088&ie=UTF8&t=k&ll=38.633282,-90.145204&spn=0.006336,0.020599&z=17

This one will look a tad less splatted when it is rebuilt in the next four years for the Great Lemon Bridge for I-70 - some of the demolition/grading for said bridge project is visible NW of the Tri-Level.

[The Premier]

2. Wooster OH: This was staged construction, but huh?

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&ll=40.796333,-81.912775&spn=0.018161,0.033088&t=k&z=15

Prior to ODOT expanding the U.S. Route 30 freeway from Wooster to before Ohio SR 57, U.S. 30 had to travel on a two-lane road after that interchange.

[Bickendan]

The only one that made me cringe was the Breezewood on US 30. Wait, Breezewood IS on US 30, nevermind.

[exit322]

2. Wooster OH: This was staged construction, but huh?

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&ll=40.796333,-81.912775&spn=0.018161,0.033088&t=k&z=15

I think you answered your own comment there.  Instead of ripping everything apart (as Lincoln Way, old 30, still has a fair amount of business), they kept one at-grade ramp in the cloverleaf (3/83/"to 250" south to 30 east) - while it'd be nice for no at-grade on that particular loop, it's not too bad - there's a de facto extra lane when turning and there usually isn't much of a wait to go that-a-way.

It was far worse before when that ramp from 30 EB to 250/83 EB/SB was also the exit-to-stay-on-US 30 (and 30 became that two-lane mess on Lincoln Way for about 3 miles).  Finishing the 4-laning there saved at least 5 minutes, even on a good day.

[vdeane]

I'm sure the eastern interchange between I-490 and the Inner Loop counts: http://maps.google.com/maps?ie=UTF8&hl=en&hq=&hnear=Rochester,+Monroe,+New+York&ll=43.149986,-77.603366&spn=0.005683,0.013894&z=17

It's pretty crazy.  Two ramps from South Ave to I-490 east; no access from local streets to I-490 west (and formerly east, until the ramp from Byron St was aligned that way; it was formerly a loop ramp from the Inner Loop, giving it two ramps to I-490 east as well) and no access from I-490 west to the Inner Loop.  The complex interchange and double connections are the result of I-390 being canceled and rerouted north of I-590; it was to end here.

I'd say the Bruckner interchange in NYC definitely qualifies too.

[Truvelo]

There's been a few comments made about the I-75/US-30 interchange so I've had a go at improving it.

Rather than flatten everything and start again I've decided to make use of what's already there. One side effect of this is there's now two bypasses around Beaverdam. At it happened, the railroad that Froggie mentioned isn't in the way of my improvements as the westbound US-30 to southbound I-75 connection fits quite perfectly further east.

[deathtopumpkins]

But on your map how does someone go from westbound US 30 to northbound I-75? The only option I can see is getting off US 30 on Ohio 696 and then getting on I-75 at exit 135.

[Truvelo]

But on your map how does someone go from westbound US 30 to northbound I-75? The only option I can see is getting off US 30 on Ohio 696 and then getting on I-75 at exit 135.

That is deliberate. There's little point in having direct connections between westbound US-30 to northbound I-75 and eastbound US-30 to southbound I-75 as there are local roads that cut the corner. In the example you've given Ohio 235 or Bentley Road would be used at it's half the distance of US-30 and I-75 to exit 140.

[Michael]

It's pretty crazy.  Two ramps from South Ave to I-490 east;

Even as a roadgeek, that creeped me out the first time going through that intersection.  I thought we were in the wrong lane because I saw the sign on the opposite side of the road first.

The complex interchange and double connections are the result of I-390 being canceled and rerouted north of I-590; it was to end here.

That would have made that interchange worse then it already is.

My contribution is I-81/I-690 in Syracuse, NY.  It has slip ramps for most of the connections, and a flyover from west to south and no direct connection from south to west and east to north.  Bear St/NY 298 about a mile to the west is used for this connection.

[Truvelo]

Most of the examples listed so far are due to sections of the interchanges being built at different times or because a road joining the interchange was never built.

In the last map at Syracuse, the interchange shown looks complete but around 5 miles to the west there is a freeway section of route 5 that is incomplete at both ends. Assuming the eastern end was meant to continue beyond W Genesee St to I-81 then it could have removed some of the traffic from the I-81/I-690 interchange.

[froggie]

In the last map at Syracuse, the interchange shown looks complete but around 5 miles to the west there is a freeway section of route 5 that is incomplete at both ends. Assuming the eastern end was meant to continue beyond W Genesee St to I-81 then it could have removed some of the traffic from the I-81/I-690 interchange.

Not really.  The proposals for that part of NY 5 involved a connection into downtown (but not to I-81) and/or a long arcing loop around to I-81 south of Nedrow.  Neither would have pulled traffic from the 81/690 interchange, and the former might've even ADDED more traffic to 81/690.

[agentsteel53]

the seemingly worst-planned interchange I have ever seen is Laval Road on I-5 just north of the Grapevine.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Laval+Road,+Lebec,+CA&sll=37.0625,-95.677068&sspn=46.812293,68.554688&ie=UTF8&hq=&hnear=Laval+Rd+W,+Lebec,+Kern,+California+93243&ll=34.986427,-118.945584&spn=0.011902,0.016737&z=16

note the two distinct segments of Laval Road.  The east one is next to impossible to navigate to, given the absence of signage - and the general lack of indication that, oh yeah, the freeway cut it in half.

[Troubleshooter]

1. Beaverdam OH: I-75 and US-30 come together with two different interchanges that connect to a county road that used to be US-30.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=beaverdam+OH&sll=41.882626,-87.645772&sspn=0.002249,0.004136&ie=UTF8&hq=&hnear=Beaverdam,+Allen,+Ohio&ll=40.830762,-83.974771&spn=0.036563,0.066175&t=k&z=14

That is diabolical. Why go to the effect of building a large freeflow interchange on US-30 when it doesn't even connect to I-75. It reminds me of Breezewood and I see there's already a growing cluster of gas stations and fast food restaurants ready to take money from turning traffic.

Something else I noticed in the area is further east at Williamstown where US-68 crosses the old US-30 alignment the bridge over US-68 has been removed. It seems the bypass around Williamstown being being reduced to two lanes and the bridge replaced with an at-grade junction.

A little history here.

When I-75 was built, the diamond interchange was with US-30.

Next, they built the divided segment of US-30 west of Beaverdam. They put in a half diamond with old US-30, including a bridge. A temporary left turn ramp was built under the bridge for US-30 traffic. Originally, US-30 was to be routed north of the old route.

When US-30 was changed to go south of the old route, the trumpet interchange was put in, and the overpass on old US 30 was replaced with an at-grade intersection.

Actually, the traffic movements that are used the most are connections between US-30 to the west and I-75 to the north.

6. New London CT: If anyone can explain this, I'm listening.

This one's actually simple.  You have a local access interchange, and immediately adjacent to it is a 3/4 interchange shoehorned in for a cancelled freeway.

But it isn't a 3/4 interchange. it's a 5/8 interchange. There are three left turns and two right turns. In addition, there are ramps for only eastbound traffic to have access to two local streets not directly connected to the rest.

7. Pook's Hill MD: Can't make many turns

Technically considered part of Bethesda.

And for this one, you have to look at history.  Rockville Pike is the original US 240.  I-270 was built first with US 240 rerouted onto it.  Then the Beltway was built to the east.  Then finally the Beltway to the west.  But since this area was already somewhat developed by the time the Beltway was built, both it, some of the interchange ramps, and Metro's Red Line had to be shoehorned into the available right-of-way, nevermind that you have Rock Creek Park adjacent to the eastern third of the interchange.

the problem is that, when it was opened,. people wanted to make the missing turns. So they installed a jughandle just north of the interchange to let drivers make U-turns. The northbound to eastbound ramp was added later. Southbound traffic wanting to go to either of the freeways to the west, and Eastbound traffic wanting to go north are signed to make turns on surface streets to use the next interchange to the west.

8: The Birmingham AL "Hubris" Interchange:

This one may look weird, but consider the loop ramp near the bottom has long been closed to traffic.  So the remaining ramps effectively serve as a half-interchange to/from the south.

But note that the northbound exit loop ramp is bridged over what is effectively the entrance ramp (connects farther north).

If you look around at the surroundings a lot of those interchanges make perfect sense.

For example, #5: The GSP SB to 19 NB and 19 SB to GSP NB connections are facilitated by I-80 to the north.
And #7: Why would you want to use any of the missing connections there? All of the freeway-freeway connections are facilitated by the other I-270 spur.

And, excepting the US 30 / I-75 example, I daresay most of those interchanges are partials or funky configurations because that is all that either traffic volumes warrant or space and budget allow for.

US DOT regulations now discourage partial interchanges.

Your two examples along US 30 in Ohio are relatively tame compared to this interchange complex west of Marysville for US 33/36, Oh 4/245
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Wooster+OH&sll=40.830762,-83.974771&sspn=0.036563,0.066175&ie=UTF8&hq=&hnear=Wooster,+Wayne,+Ohio&t=k&ll=40.2398,-83.402796&spn=0.015757,0.038495&z=15

That's just a trumpet with local connections added. At least all of the turns are possible.

4. North Caldwell, NJ

This one could've been fine as a stack or cloverleaf, but unfortunately US 46 runs too close to the interchange for that to work.

Note that the US-46 interchange was there first. My comment is that the interchange allows all possible turns, except that traffic exiting from I-80 eastbound can't go anywhere but east on US-46. To get to NJ-23, traffic has to go to the next interchange to the east and use both loop ramps.

[realjd]

That is deliberate. There's little point in having direct connections between westbound US-30 to northbound I-75 and eastbound US-30 to southbound I-75 as there are local roads that cut the corner. In the example you've given Ohio 235 or Bentley Road would be used at it's half the distance of US-30 and I-75 to exit 140.

I grew up nearby in Fort Wayne. US-30 east to I-75 south is the quickest way to get to Dayton or Cincy from there. Cutting the corner involves driving through Lima, which is slow, while US30 has a high 65mph speed limit.

It's pretty crazy.  Two ramps from South Ave to I-490 east;

Even as a roadgeek, that creeped me out the first time going through that intersection.  I thought we were in the wrong lane because I saw the sign on the opposite side of the road first.

WB SR-836 to SB SR-826 in Miami. There's two ramps. One is a left exit flyover ramp, the other is a loop. When they built the newer flyover, they didn't remove the loop ramp because it provided better access to the Flagler Rd. and US-41 exits.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=25.779566,-80.318663&sspn=0.007149,0.009645&g=Lima,+Allen,+Ohio&ie=UTF8&ll=25.779566,-80.320712&spn=0.007149,0.013733&t=k&z=17

[deathtopumpkins]

Troubleshooter: USE THE EDIT BUTTON.

US DOT regulations now discourage partial interchanges.

Link?

I hardly think it would be constructive to disallow partial interchanges where only a partial interchange is needed.

[Bickendan]

the seemingly worst-planned interchange I have ever seen is Laval Road on I-5 just north of the Grapevine.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Laval+Road,+Lebec,+CA&sll=37.0625,-95.677068&sspn=46.812293,68.554688&ie=UTF8&hq=&hnear=Laval+Rd+W,+Lebec,+Kern,+California+93243&ll=34.986427,-118.945584&spn=0.011902,0.016737&z=16

note the two distinct segments of Laval Road.  The east one is next to impossible to navigate to, given the absence of signage - and the general lack of indication that, oh yeah, the freeway cut it in half.

At least the interchange design itself is fairly benign.

[Eth]

It's pretty crazy.  Two ramps from South Ave to I-490 east;

Even as a roadgeek, that creeped me out the first time going through that intersection.  I thought we were in the wrong lane because I saw the sign on the opposite side of the road first.

WB SR-836 to SB SR-826 in Miami. There's two ramps. One is a left exit flyover ramp, the other is a loop. When they built the newer flyover, they didn't remove the loop ramp because it provided better access to the Flagler Rd. and US-41 exits.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=25.779566,-80.318663&sspn=0.007149,0.009645&g=Lima,+Allen,+Ohio&ie=UTF8&ll=25.779566,-80.320712&spn=0.007149,0.013733&t=k&z=17

Similarly, there are two ramps from SB I-75 to EB I-285 on the north side, though in this case they're both right exits.  Neither one really provides access to anything the other doesn't.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Marietta,+GA&sll=37.0625,-95.677068&sspn=32.939885,72.949219&ie=UTF8&hq=&hnear=Marietta,+Cobb,+Georgia&ll=33.893431,-84.46332&spn=0.01685,0.03562&t=h&z=15

[Truvelo]

A little history here.

When I-75 was built, the diamond interchange was with US-30.

Next, they built the divided segment of US-30 west of Beaverdam. They put in a half diamond with old US-30, including a bridge. A temporary left turn ramp was built under the bridge for US-30 traffic. Originally, US-390 was to be routed north of the old route.

When US-30 was changed to go south of the old route, the trumpet interchange was put in, and the overpass on old US 30 was replaced with an at-grade intersection.

Actually, the traffic movements that are used the most are connections between US-30 to the west and I-75 to the north.

Thanks for that. That explains the unusual layout in the area but there's a few things that still need answering. The aerial imagery clearly shows right of way for east facing ramps at exit 134. I'm sure I am correct in saying this hasn't been carried out due to the close proximity to exit 135 and the associated weaving.

The other thing that puzzles me is the huge trumpet that replaced the half diamond. Surely any potential pinch point is going to be the stretch of former US-30 between here and I-75 which all traffic transferring between the two routes will have to use therefore the massive freeflowing trumpet seems to be wasted.

[Troubleshooter]

WB SR-836 to SB SR-826 in Miami. There's two ramps. One is a left exit flyover ramp, the other is a loop. When they built the newer flyover, they didn't remove the loop ramp because it provided better access to the Flagler Rd. and US-41 exits.

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=&sll=25.779566,-80.318663&sspn=0.007149,0.009645&g=Lima,+Allen,+Ohio&ie=UTF8&ll=25.779566,-80.320712&spn=0.007149,0.013733&t=k&z=17

You didn't notice the missing ramp? Northbound traffic has to turn the wrong way, and then take two loop ramps at the next interchange to the east to make a left turn there. There are stubs where the missing ramp was removed to put in the directional ramp you mentioned.

The loop ramp has a low clearance that big trucks can't use. But the flyover misses two exits.

A little history here.

When I-75 was built, the diamond interchange was with US-30.

Next, they built the divided segment of US-30 west of Beaverdam. They put in a half diamond with old US-30, including a bridge. A temporary left turn ramp was built under the bridge for US-30 traffic. Originally, US-30 was to be routed north of the old route.

When US-30 was changed to go south of the old route, the trumpet interchange was put in, and the overpass on old US 30 was replaced with an at-grade intersection.

Actually, the traffic movements that are used the most are connections between US-30 to the west and I-75 to the north.

Thanks for that. That explains the unusual layout in the area but there's a few things that still need answering. The aerial imagery clearly shows right of way for east facing ramps at exit 134. I'm sure I am correct in saying this hasn't been carried out due to the close proximity to exit 135 and the associated weaving.

Correct. The Federal DOT discourages ramps closer than 1 mile. So they took them out. They were there in the 1960s.

The other thing that puzzles me is the huge trumpet that replaced the half diamond. Surely any potential pinch point is going to be the stretch of former US-30 between here and I-75 which all traffic transferring between the two routes will have to use therefore the massive freeflowing trumpet seems to be wasted.

It puzzles me too. But it uses less right of way than a diamond would. And it was patched into the existing road while maintaining traffic. They tore out the half diamond after the trumpet was finished. The current intersection is where the westbound on ramp was.

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Troubleshooter: USE THE EDIT BUTTON.

The phrase "Use the edit button" is vague, because:

- I don't SEE an "edit" button. It says "modify".

- Out of context, that phrase makes no sense at all as a comment on what to do. I now know what you mean, but that phrase is totally useless to a new user. I thought I had a typo that needed fixing (I did, and  I fixed it). And the comments on the right way to do it were just as vague. How about "Please combine your replies to different posts into one post" instead?

Did I do it right this time?????? I hope I got it right.

US DOT regulations now discourage partial interchanges.

Link?

I hardly think it would be constructive to disallow partial interchanges where only a partial interchange is needed.

I don't have a "link" because my source is on paper. It is a manual on interchange design in our library. I copied just the page it was on, so I don't know where I got it.

They disallow partial interchanges, because too many drivers make illegal movements when they discover that the interchange (which their map led them to) will not allow the turn they want to make. It causes wrong way ramp driving and U-turns on the freeway.

There are two partial interchanges in my area, and I have seen several drivers who expected to be able to to turn the other way drive on the ramps in the wrong direction.

The only places partial interchanges are not discouraged are:

- Where a business route forks off the main route on both sides of a city.

- Where a low traffic interchange is too close to a higher traffic interchange to allow the remaining ramps. This interchange takes a load off the main interchange.

What is now specifically discouraged is the use of partial interchanges to force drivers to go through at least one toll plaza before they can exit. The Garden State Parkway is notorious at this. Many drivers used the police U-turn spots to turn around, because they (again using maps) found that they could not exit where their destination was.