Two lane exit from single lane

[briantroutman]

Driving across Wyoming a couple of days ago, I noticed this unusual configuration on I-80 at Exit 209 (Johnson Road) just west of Rawlins. The westbound offramp is two lanes (and is signed as a "two lane exit" on a snow emergency sign), but both lanes branch off the single right lane, rather than the common configuration of a dedicated exit-only #3 lane plus the optional #2 lane.

I'll assume that, in practice, the second exit lane is typically used only when the gates are down and I-80 is closed, and traffic simply moves from the left and right through lanes to both exit lanes, even though it isn't striped as such.

Snow emergencies aside, are there any other locations where a two-lane exit branches off a single lane? Is this even technically allowable under the MUTCD?

[jakeroot]

Incredibly common in England the UK (and other countries), less so here. One example near me (WA-509 at Port of Tacoma Road near Tacoma, Wash):

[wxfree]

Just today I drove through an example of the opposite situation.  On I-20 west of Fort Worth, I-30 exits to the left with three lanes.  I-20 approaching the exit has four lanes.  The second lane from the right doesn't go to both roads.  It's what I call a "hard split," with each lane leading to one road.  The right lane divides into two lanes, non-exit lanes carrying the through route. https://www.google.com/lochp?ll=32.725306,-97.580878&spn=0.003064,0.005681&t=k&z=18

Another opposite situation is in Stephenville, TX, although it doesn't include a true exit.  US 67/377 has two northbound lanes, and Business US 377 is straight ahead on both lanes, while US 67/377 "exits" into two lanes.  The right lane divides before the "exit" and the short middle northbound lane soft splits, so it isn't a prime example, but it's still interesting.  https://www.google.com/lochp?ll=32.20678,-98.231011&spn=0.000766,0.00142&t=k&z=20

[vtk]

Until last year, there were good examples of this on I-270 either side of the Scioto River south of Columbus. Not only were there two-lane exits without dropped lanes, but two-lane entrances that merged completely into the right mainline lane.

[empirestate]

The local drivers have decided that this exit works that way. The ramp is two lanes wide immediately after exiting, so people regularly split themselves into two queues in the right lane at the gore point (and since the ramp always backs up during rush hours, this of course makes the right lane useless for its also-intended function as a through lane). Unfortunately, none of the Street View vintages shows traffic in its full glory, so you'll have to take my word for it.

[Bitmapped]

As noted previously, Ohio sometimes does it this way.  The US 250 split from I-77 at New Philadelphia is the same way. https://goo.gl/maps/86X93

[vdeane]

The mainline of I-87 does this: https://www.google.com/maps/@42.6973125,-73.8383047,299m/data=!3m1!1e3

[briantroutman]

Thanks for all of the links.

The mainline of I-87 does this: https://www.google.com/maps/@42.6973125,-73.8383047,299m/data=!3m1!1e3

Some of the examples given are in kind of a gray area as to whether they're the same thing as what I described, but if you're referring to the 1W ramp to the toll plaza, then I'd say it's definitely a different setup. There, the right lane is a dedicated exit only lane which then expands to two lanes well after the gore point.

What I'm talking about (and what's shown in the example I linked) is a situation where there's no lane drop, and the striping is such that the right lane has the option of sliding into either of two exit lanes directly from the right through lane.

As noted previously, Ohio sometimes does it this way.  The US 250 split from I-77 at New Philadelphia is the same way. https://goo.gl/maps/86X93

This is very close, although it's slightly different from the Wyoming example in that it doesn't have two definite, separate theoretical gores (one for each lane) touching the right hand edge line of the through lane. It's like 3/4 of the way between vdeane's example above (split well after the gore) and the WY example with the two very definite gores.

The local drivers have decided that this exit works that way.

Same comment here, although as was pointed out, this has more to do with the way motorists use it rather than how it was striped.

Just today I drove through an example of the opposite situation....

I think you accidentally gave us the same link twice.

One example near me (WA-509 at Port of Tacoma Road near Tacoma, Wash):

This is almost exactly the same thing–main visual difference is that the striping is less vivid. And there is another slight difference: even though WA 509 appears to be the through route here, it's signed as if it's the exit (a left exit), with the other branch to the right being unsigned. If they do want to treat WA 509 as an "exit" , the leftmost lane should be signed as "Only" .

[jeffandnicole]

...but two-lane entrances that merged completely into the right mainline lane.

The NJ Turnpike's PA Extension onto the NJ Turnpike North mainline essentially works this way.

[roadman65]

If I assume you are talking about a through lane branching off into a two lane exit, then the Southbound Garden State Parkway at Exit 129 does this.

Edit: It used to do this, I just checked on it and the NJTA widened (well not exactly, but shrunk the size of the travel lanes and shortened the shoulders) the Parkway to five lanes each way, so now this does not count.  However it did probably, if that is what the OP is looking for as it was four lanes where one lane became two lanes.

[wxfree]

I think you accidentally gave us the same link twice.

I did.  I'll correct it.

[TheHighwayMan3561]

I-94 eastbound at Carmichael Road in Hudson, WI.

[jakeroot]

One example near me (WA-509 at Port of Tacoma Road near Tacoma, Wash):

This is almost exactly the same thing–main visual difference is that the striping is less vivid. And there is another slight difference: even though WA 509 appears to be the through route here, it's signed as if it's the exit (a left exit), with the other branch to the right being unsigned. If they do want to treat WA 509 as an "exit" , the leftmost lane should be signed as "Only" .

I drive the road quite regularly. I assure you, the signs are just fucking horrible WSDOT incompetence. The 509 mainline follows the lane lines shooting to the "left" (if you will).

[empirestate]

The local drivers have decided that this exit works that way.

Same comment here, although as was pointed out, this has more to do with the way motorists use it rather than how it was striped.

That's what I mean. The way it's striped, it isn't quite what you're looking for, but the way people actually drive it, it exactly is, with the two "gores" and everything.

[ekt8750]

but two-lane entrances that merged completely into the right mainline lane.

There are many ramps on I-76 the Schuylkill Expressway that do just that and the bottlenecks they create are the worst.

[Bickendan]

I-205 nb -> WA 14

Somewhat common in California, though CalTrans is rather fond of sudden lane adds, as seen from this shot of I-210's ramps coming off mainline sb I-5. https://www.google.com/maps/@34.31877,-118.493437,3a,75y,340.12h,94.95t/data=!3m4!1e1!3m2!1soZ4j0ww0oW8qV1dzX5Ejzw!2e0

[Joe The Dragon]

I think the old PA / NJ turnpike interchange had 3 lanes that just kind of fanned out 1 right lane.

[Truvelo]

Incredibly common in England the UK (and other countries), less so here.

Yes, virtually all exit ramps here have two lanes.

Was also standard for entrance ramps to have two lanes up to and including the merge point like this. Junctions built after the early 1990s no longer had merges like this due to safety issues and the possibility of two cars side by side trying to join at the same time.

[freebrickproductions]

Not a highway nor an exit-like-thing, but here's an interesting situation here in Huntsville: https://www.google.com/maps/@34.763613,-86.573558,3a,66.8y,78.68h,72.29t/data=!3m4!1e1!3m2!1sRETdRkEcXd-zQBE_4Ci99w!2e0

[Truvelo]

^^ I've seen plenty of examples like that both here and abroad where one way streets are narrowed at the end to deter traffic from entering the wrong way.

[briantroutman]

There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.



The two key characteristics are: 1.) No lane drop, and 2.) Two theoretical gore points (one for each exit lane) touching the edge line of the through lane.

There's a bit of a gray area between #1 and #5, but I think the distinction is relevant. With the striping in #1, two cars riding nose-to-tail in the right lane could exit simultaneously–easily and neatly. Even though the pavement surface is essentially identical in #5, the striping forces it to act more like #4, where vehicles would exit single file and then fan out to fill both lanes where the divider striping appears.

[jakeroot]

It does seem that people are having a hard time understanding what you are talking about.

I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.

[briantroutman]

I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.

It would perhaps be a little less clear than the solid line example, but yes, I'd say it counts. I used the solid line primarily because that's what I encountered on I-80 in Wyoming.

[jakeroot]

I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.

It would perhaps be a little less clear than the solid line example, but yes, I'd say it counts. I used the solid line primarily because that's what I encountered on I-80 in Wyoming.

Okay, good. Washington and California's solid lane lines always end at the theoretical gore point, so example 1 would technically not be allowed (since the solid lane line extends past the theoretical gore).

[hbelkins]

Until I-64 was widened near Winchester, the exit to the Mountain Parkway qualified.