Longest turns at intersections (excluding SPUIs)

[jeffandnicole]

Looking back at some of the jughandle lefts posted, then I can find several in NJ that are at least 4/10th to 1/2 mile long.  NJ 70 in the Cherry Hill area has a few of these.

[roadman65]

If you knew the SPUI in Lakeland, Florida at I-4 and US 98 you would make the exception as I-4 has a super wide median, planned for the rail  line that Dick Scott vetoed when he was our governor, but nonetheless as the longest turn for a SPUI as the point from the ramps to the straight point it turns to is more than twice that of an ordinary SPUI.

The CR 611 and SR 580 interchange near Safety Harbor in Florida has a shallow angle crossing that needs three span wire assemblies there to mount the signal heads needed to control that intersection.

[doorknob60]

This half-SPUI in Langley, BC has a relatively long stretch to clear as well (Google Maps). The signal to the north creates some pretty significant backups, so you get a fair bit of this.

That's a great example Jake!  That streetview link with traffic backing up through the offf-ramp intersection sums up perfectly the concern i have regarding this type of SPUI design.  Also in that streetview i noticed there is a no right on red sign.  It's fine getting a green when traffic along the arterial is backed up through the intersection (and the arterial traffic that cleared the SPUI are given no indication that the off-ramp traffic has a dedicated green arrow) but don't turn right on red!

This can happen at more traditional intersections, too. It's very common at the I-84/ID-55 intersection, pretty much every rush hour. Street view didn't catch the congestion but it looks just like Jake's example https://www.google.com/maps/@43.5976785,-116.3543316,3a,75y,277.35h,75.49t/data=!3m6!1e1!3m4!1swHhQb3Of67oxAr3QrQLF3Q!2e0!7i13312!8i6656 .

Right on red is also banned here. Maybe for the best since the speed limit is 50 and you'd have to go way past the stop bar to see well. Interestingly, the SPUI 2 miles to the west, does allow RTOR (from both lanes), but the geometry is better and the speed limit is 35. When that SPUI first opened, RTOR was prohibited, but it didn't take long (also people were blatantly ignoring the restrictions, probably due to other SPUIs in the area, though single lane rights, still allowing it, plus the old intersection it replaced allowing it) before they decided to allow it.

I measured a couple of SPUIs around Boise to see how long it takes to clear the intersection while turning left, and the max was about 450 ft, well shy of the 550 ft posted earlier. Even these have very long all red phases (I'm very familiar with the I-84/Vista one). I can't say I've timed it, but it feels like at least 5 seconds (for comparison, normal intersections in Ada County have 1 second all red phases).

[thspfc]

There's quite a few in Milwaukee. Fond du Lac Avenue and Capitol Drive is the most notable.

[michravera]

I was making a left turn a few days ago from southbound I-5 in Tacoma, to eastbound WA-512, when it occurred to me (after having shifted into 3rd before I was finished turning) just how long of a turn it is. It replaced a congested loop about twenty years, and has three left turn lanes (unusual in WA), so it was important to make the turn fairly long and not tight.

Measured out, from the center of the stop line, to the point where the dashed markings become regular lane lines (usually after a crosswalk), the turn is about 180 feet in length (longer for the outside lane @ 188 feet).

So, can you guys think of any exceptionally long turns in your area?

Only rule (right now) is that it's not a SPUI (since those always have long turns). No rules about number of crossed lanes, etc. I'm just looking at length.



For an idea of how this would be measured, just use the Google Maps measuring tool. If there's two lanes, an average would be nice.

I would have to think that a number of the "park with trees in the middle" Avenidas in South America (some of which are over 100 m wide) would have some pretty long left turns, particularly, if two such roads met.

Several of the crossings of Las Vegas Blvd in Las Vegas are going to be contenders.

The Olympic Expressway in Seoul (which has at least some pedestrian crosswalks) is close to 100 m wide and so has some pretty long left turns, but I don't recall many that were much longer than they needed to be, but the road doesn't meet all of the cross streets at right angles, so some of the "slight left jogs" may be quite lengthy.

But the champions are going to be HOV-to-HOV connecting ramps. I don't believe that it is even close to the champ, but the HOV-to-HOV ramp connecting SB I-880 to WB CASR-237 in Milpitas, CA has "can't change lanes" distance of close to 10 km.