Tightest Curve on a Motorway?

[Burns]

The problem with the M90 spur northbound slips isn't the single lane but the fact that no matter what time of day it is, you're always stuck behind a heavy trying to haul its load up that hill at 5mph. Then when you try and overtake once the slips merge together, the 1.nothing fake SUV between you and the truck tries to overtake at 6mph.

[tom66]

Are you including Urban Motorways (apologies if any of these have been posted...)

This one joining the A64(M) in Leeds is pretty tight, and it's under blue signs:
https://www.google.co.uk/maps/@53.80193 ... 384!8i8192

Technically, this is almost 90 degrees - at a give-way sign!
https://www.google.co.uk/maps/@53.80494 ... 384!8i8192

... though arguably it is stretching the definition of "curve" somewhat to the breaking point.

[Hagbard]

That sliproad has been a single lane for as long as I can remember, certainly for the last 30 years. The second lane used to end about where that streetview photo was taken, prior to the current layout where the sliproad is a lane drop. The sliproad from the Friarton Bridge towards the Broxden spur (https://goo.gl/maps/wibmwCtzvUoGj6B79) had 2 lanes until about 10 years ago - are you thinking of this instead?

Photo as built shortly before the opening of the Broxden spur in 1978. All of the slip roads were marked out with two lanes.

[Duncan macknight]

That sliproad has been a single lane for as long as I can remember, certainly for the last 30 years. The second lane used to end about where that streetview photo was taken, prior to the current layout where the sliproad is a lane drop. The sliproad from the Friarton Bridge towards the Broxden spur (https://goo.gl/maps/wibmwCtzvUoGj6B79) had 2 lanes until about 10 years ago - are you thinking of this instead?

Photo as built shortly before the opening of the Broxden spur in 1978. All of the slip roads were marked out with two lanes.

That’s a cracking photo! Must be sometime in May 1978 as that’s when the Broxden spur opened.

[Lockwood]

What was the radius of the bottom of the A3(M) mainline before they adjusted it?

They adjusted the bend on a bridge removing the hard shoulder.
Before that, it had a 50 limit due to the curve.

[AndyB]

Has nobody mentioned our M2?
Greencastle, mainline northbound and offslip with a very sharp turn
J5 Templepatrick with very sharp curves on the onslips
J11 with the A42

Of course, the radius of the roundabout at M1 J11 is a little bit tighter than the examples we've seen so far!

[JackieRoads]

M5 J22 has a darn tight bend especially for the loop. https://www.google.com/maps/@51.2360454 ... a=!3m1!1e3

[paully]

That sliproad has been a single lane for as long as I can remember, certainly for the last 30 years. The second lane used to end about where that streetview photo was taken, prior to the current layout where the sliproad is a lane drop. The sliproad from the Friarton Bridge towards the Broxden spur (https://goo.gl/maps/wibmwCtzvUoGj6B79) had 2 lanes until about 10 years ago - are you thinking of this instead?

Photo as built shortly before the opening of the Broxden spur in 1978. All of the slip roads were marked out with two lanes.

Thanks for sharing, and I stand corrected! It looks so different to today.