Smallest Radii on loop ramp

[johndoe]

Hey everyone, I'm curious to see what sort of radii are used across the country for loop ramps.  Let's see how small they'll go!  It's ok if it is leading to a CD system, too.  Let's see those Google locations!

[kphoger]

One of my favorites from México:
http://goo.gl/maps/zyxpZ

[johndoe]

That one might be tough to beat haha!  For some reason that reminded me of this one:
http://goo.gl/maps/Y8UAO

[tradephoric]

Here's one near Inkster, Michigan.  Think it has been posted on this forum on another thread recently:
http://maps.google.com/maps?ll=42.299465,-83.271759&z=17&t=h&hl=en

[cpzilliacus]

Exit from I-895 (Baltimore Harbor Tunnel Thruway) southbound to Southbound Md. 2 (Potee Street) (Exit 7) is pretty sharp.

And there is this interchange of I-495 (Capital Beltway) at Md. 97 (Georgia Avenue) in Silver Spring, Maryland has three sharp loop ramps (Exit 31).

[Some_Person]

Here are some I've found—

http://goo.gl/maps/Ve3Wf US 22 & PA 145

http://goo.gl/maps/Oqw75 I 80 & I 81

Not a loop ramp, but still; http://goo.gl/maps/BIA5s

http://goo.gl/maps/mfGWg GSP at US 1

http://goo.gl/maps/7gyI2 US 22 at PA 611

http://goo.gl/maps/ZcQkm US 22 at Fullerton Ave (you can tell from my selections that The Lehigh Valley Thruway has a lot of tight ramps )

http://goo.gl/maps/NVhU2 PA 581 and US 15

[Alps]

Here's one near Inkster, Michigan.  Think it has been posted on this forum on another thread recently:
http://maps.google.com/maps?ll=42.299465,-83.271759&z=17&t=h&hl=en

I think I posted it as a "best of" in the sense of aesthetics and intrigue. Anyway, I can't beat it, but here are some in NJ.
EDIT: MORE

[NE2]

Here's one at a trumpet, constrained by the Niagara Escarpment: http://maps.google.com/maps?hl=en&ll=43.235195,-79.828463&spn=0.003564,0.008256&gl=us&t=k&z=18

[johndoe]

Here's one at a trumpet, constrained by the Niagara Escarpment: http://maps.google.com/maps?hl=en&ll=43.235195,-79.828463&spn=0.003564,0.008256&gl=us&t=k&z=18

Holy cow...check out this little junction to the southeast!  http://goo.gl/maps/kGdU1  Don't think I've ever seen anything like THAT before!

[Kacie Jane]

http://goo.gl/maps/wH2gM  This I-5 on-ramp annoys me to the point where I hardly ever use it.

[NE2]

Holy cow...check out this little junction to the southeast!  http://goo.gl/maps/kGdU1  Don't think I've ever seen anything like THAT before!

I-10/I-20 is just like that with a bridge (and a lot bigger)

[Bickendan]

How about this one on CA 110... http://goo.gl/maps/gQZAY

[jeffandnicole]

Seemingly nearly every trumpet interchange on the PA Turnpike would qualify.  One of the tightest ones is the I-76 (Schuykill Expressway) to I-76 (PA Turnpike) ramp in the King of Prussia Area. http://goo.gl/maps/RFF5h

[1995hoo]

I haven't attempted to click through every link in this thread, so apologies if this has already been posted. The Merritt Parkway in Connecticut has a bunch of tight ramps and this one is a loop-around without an acceleration lane: http://goo.gl/maps/NOMHm

Another from further east: http://goo.gl/maps/vI0M7


Going from Cropsey Avenue to the Belt Parkway in Brooklyn....at least there's an acceleration lane: http://goo.gl/maps/1MkLS

[deathtopumpkins]

Watch and learn, rest of the country:

http://goo.gl/maps/ZT07B MA 128/1A
http://goo.gl/maps/WH14G MA 128/35 (note, reconstructed as a diamond, opened this summer)
http://goo.gl/maps/rDLC7 MA 128/Lowell St
http://goo.gl/maps/OpFPR US 1/Walnut St
http://goo.gl/maps/KrlFK US 1/Main St
http://goo.gl/maps/0qGzM US 1/Essex St
http://goo.gl/maps/O3nQX US1/Salem St (this one's a bit of a stretch)
http://goo.gl/maps/vl8cL Riverway/Jamaicaway/MA 9
http://goo.gl/maps/PWVE8 MA 9/Weston Rd
http://goo.gl/maps/7CBBU MA9/27
http://goo.gl/maps/Jo1Pn MA9/30/126 (this one's also a bit of a stretch)
http://goo.gl/maps/cxtZN MA9/85
http://goo.gl/maps/n10yq MA146/Elm St
http://goo.gl/maps/RN7DQ MA2/12

[colinstu]

http://goo.gl/maps/ZT07B MA 128/1A

Surprised they wouldn't configure the lanes more like this.



North-bound Dodge Street is already one lane (look @ bottom) ... why make it two lanes after the intersection and then force all the people on the loop ramp (look at em all! the whole ramp is clogged) with people who have to Yield/stop for people for nearly no reason. What I drew is a little more free flow from what I can tell from the current situation they got going on there.

[deathtopumpkins]

It's Massachusetts. It's not supposed to make sense.

Seriously though, that would make much more sense. I take that ramp frequently when visiting my mother in Ipswich, and it's almost impossible to pull out onto 1A because people don't know whether northbound traffic will end up in the right or left lane. And yes, traffic usually backs up the whole length of the ramp. Last time I drove it exiting traffic on 128 actually backed up in the right lane to before the onramp from 1A southbound.

[1995hoo]

http://goo.gl/maps/ZT07B MA 128/1A

Surprised they wouldn't configure the lanes more like this.



North-bound Dodge Street is already one lane (look @ bottom) ... why make it two lanes after the intersection and then force all the people on the loop ramp (look at em all! the whole ramp is clogged) with people who have to Yield/stop for people for nearly no reason. What I drew is a little more free flow from what I can tell from the current situation they got going on there.

Yup. They could even make it a part-time thing depending on how the traffic is at different times of day. That's done in the District of Columbia during rush hours near the Lincoln Memorial (see here: http://binged.it/Y5cgkK –Google's image shows the road under construction and is confusing). Notice the sawhorse sitting in the grass near the end of the ramp. During rush hour they put out that sawhorse and some traffic cones to allow traffic coming down the ramp to continue without slowing to yield. But some dummies insist on stopping to yield anyway and it's damn annoying! If you zoom out slightly–for me it was two clicks of the scrolly wheel thing on my mouse–you'll see what happens when they don't put out the cones.

[colinstu]

Guess I'll go ahead and contribute a little.

http://goo.gl/maps/1T8Ke Silver Spring Rd and & Sherman Blvd... ugly and one of the ramps is pretty darn small.
http://goo.gl/maps/oeTsd could be a stretch... (Brown Deer Rd & I-43)

Trying to think of some more in WI... can't think of any more currently, but I mostly concentrate on South East WI.

[Roadsguy]

You mean make it one-lane from the NB off-ramp to the loop ramp merge, and have the loop make the second lane?

That would be better.

[colinstu]

You mean make it one-lane from the NB off-ramp to the loop ramp merge, and have the loop make the second lane?

That would be better.

Yep. Added lane

[kphoger]

Here's one at a trumpet, constrained by the Niagara Escarpment: http://maps.google.com/maps?hl=en&ll=43.235195,-79.828463&spn=0.003564,0.008256&gl=us&t=k&z=18

Holy cow...check out this little junction to the southeast!  http://goo.gl/maps/kGdU1  Don't think I've ever seen anything like THAT before!

Both of those are excellent examples!

I forgot about this Mexican example:  http://goo.gl/maps/tvhnp
And here's the signage on the freewawy:  http://goo.gl/maps/Vyj3x (translation:  DANGEROUS EXIT/SLOW DOWN)
What's amazing is that it's an interchange between two toll roads–one going between Acapulco and México City, and the other leading to Taxco (a tourist destination).  In fact, using that ramp is probably the fastest way to get from Acapulco to Taxco.

[TheStranger]

The cloverleaf ramps at the Route 1/Junipero Serra Freeway interchange with Brotherhood Way in San Francisco are extremely compact:

https://maps.google.com/maps?q=San+Francisco&hl=en&ll=37.712798,-122.471056&spn=0.00229,0.002376&sll=34.093051,-118.208588&sspn=0.006779,0.009506&hnear=San+Francisco,+California&t=k&z=19

[Mr_Northside]

The Westbound Blvd of the Allies ramp to the Liberty Bridge is pretty tight:

http://maps.google.com/maps?q=15222&hl=en&ll=40.436634,-79.994451&spn=0.001822,0.00284&sll=41.117935,-77.604698&sspn=5.221572,11.634521&t=h&hnear=Pittsburgh,+Pennsylvania+15222&z=19


(North is @ the bottom)

[TheStranger]

Another San Francisco example I found, the ramp for Exit 2B off of Interstate 80 westbound, to Harrison Street (which is kinda redundant with the less-challenging Fremont Street ramp nearby).

https://maps.google.com/maps?q=Bryant+%26+2nd,+San+Francisco&hl=en&ll=37.784753,-122.392416&spn=0.003235,0.004753&sll=37.78463,-122.391955&sspn=0.003252,0.004753&t=h&hnear=Bryant+St+%26+2nd+St,+San+Francisco,+California+94107&z=18

20 MPH advisory speed!

https://maps.google.com/maps?q=Bryant+%26+2nd,+San+Francisco&hl=en&ll=37.784765,-122.392827&spn=0.000809,0.001188&sll=37.78463,-122.391955&sspn=0.003252,0.004753&t=h&hnear=Bryant+St+%26+2nd+St,+San+Francisco,+California+94107&z=20&layer=c&cbll=37.784765,-122.392827&panoid=utSATZktBDrj6whW9AQJ6w&cbp=12,216.26,,0,4.06

A few miles to the south is this ramp from Interstate 280 south to Pennsylvania Avenue northbound:
https://maps.google.com/maps?q=18th+St+%26+Pennsylvania+Ave,+San+Francisco&hl=en&ll=37.763424,-122.393513&spn=0.002288,0.002376&sll=37.763446,-122.392915&sspn=0.002288,0.002376&t=h&hnear=18th+St+%26+Pennsylvania+Ave,+San+Francisco,+California+94107&z=19