Dropping a lane, but not from either edge

[Jardine]

For instance, let's say 3 lanes, northbound, goes to 2 lanes.  Instead of dropping either outermost lane, is there anyplace in the country where the center lane must merge into either or both other lanes ?

I realize this sounds like a guaranteed way to have continuous accidents, but that isn't always a consideration in laying out a highway.

[noelbotevera]

For instance, let's say 3 lanes, northbound, goes to 2 lanes.  Instead of dropping either outermost lane, is there anyplace in the country where the center lane must merge into either or both other lanes ?

I realize this sounds like a guaranteed way to have continuous accidents, but that isn't always a consideration in laying out a highway.

It's common for lanes that have an express-local setup. For a while in 2010 or so, I-81 through Harrisburg temporarily went express-local with its lanes due to construction. There were 3 lanes. The middle lane ended at the beginning of the setup, meaning the left lane was express, and the right lane was local.

[roadman65]

The ramp from the Verrazano Bridge to the Belt Parkway had two lanes converge in the center.  I do not know if it still exists but when I was there in 2001, an overhead sign warned motorists of the two lanes converging.

https://www.google.com/maps/place/Bay+Ridge,+Brooklyn,+NY/@40.605348,-74.030769,3a,66.8y,292.4h,82.82t/data=!3m4!1e1!3m2!1s9He29U-_BXosemoFLY_GJA!2e0!4m2!3m1!1s0x89c2455f3f1cab0d:0xa5a45198ea4d73d6

GSV shows it still but the overhead is gone.  Some may argue that the left lane ramp from the bridge just merges into the right lane of the Belt Parkway, however from what I see both roads are equal with traffic and you could consider it to be two 2 lane roads widening into  one 3 lane roadway.

Looks like they tried restriping the lines so that the bridge merge narrows to the right lane exclusively.  Now, though its back and may be why the sign is gone that was there in 01.

[cl94]

This happens quite often in the Cleveland area. For example, both ends of the I-271/I-480 concurrency, on I-480N at the I-271/US 422 interchange, I-281 NB at the same interchange, the I-90/I-271 interchange on I-271, WB I-90, and EB I-90, I-480 at I-77, and I-90 at I-490.

Go down to Akron and you have I-76/77 at SR 59. In Columbus, there's I-670/US 62 at I-270 and I-270 SB at the same interchange. I'm not going to link them, but it's present a couple exits further south on I-270 and another on I-70 at its western interchange with I-270.

[roadman65]

https://www.google.com/maps/place/Bay+Ridge,+Brooklyn,+NY/@40.606666,-74.032683,3a,66.8y,165.63h,93.69t/data=!3m4!1e1!3m2!1sil_GmGdjclohjYzq11hwNQ!2e0!4m2!3m1!1s0x89c2455f3f1cab0d:0xa5a45198ea4d73d6

I did not pan or zoom back far enough, but the sign I saw in 2001 is still there and it depicts both right lane of the Belt Parkway and the left bridge ramp as being equal.

So this merge does count as a lane being dropped from within the borders.  Both the left lane Belt and the right lane ramp stay consistent completely.

[US71]

For instance, let's say 3 lanes, northbound, goes to 2 lanes.  Instead of dropping either outermost lane, is there anyplace in the country where the center lane must merge into either or both other lanes ?

I realize this sounds like a guaranteed way to have continuous accidents, but that isn't always a consideration in laying out a highway.

Parts of US 62 in Arkansas have the Left Lane ending.

Missouri's "Shared Three Four Lane" have the center lane merging

[Ned Weasel]

Cases where two roadways converge and the outer lanes continue while the inner lanes merge are common.  I assumed the OP was asking about instances where a lane ends on a single roadway, without any convergence with another roadway, but the lane that ends is not an outer lane.

The case of three lanes being reduced to two is trivial and not an example of the hypothetical phenomenon in question.  Suppose three lanes narrow to two and the far-left lane continues.  Then the right two lanes merge with each other, which is logically equivalent to ending the far-right lane.  Now suppose three lanes narrow to two and the far-right lane continues.  Then the left two lanes merge with each other, which is logically equivalent to ending the far-left lane.

This only becomes interesting when you have four or more lanes within a single roadway being reduced to a lesser number of lanes.  For example, the far-left lane and the far-right lane could both continue.  Then the center two lanes would merge with each other.  I can't think of any case where this would be a good way to end a lane within a single roadway.  However, this is a common way to handle a merge when two separate roadways converge.

[jeffandnicole]

One of the closest true center lane merges would be where the NJ Turnpike merges the center lanes after the dual-dual roadway ends, after a short passing zone area.

The AC Expressway & NJ 42 have a center lane merge area as well. The unusual thing with this is that there's no signage whatsoever referring to this merge area.

[roadman65]

Better than the original end of the Truck and Bus Lanes at Exit 9 where all three lanes dropped completely before the extension to 8A took place.  At least the truck lanes afterwards had continuous lanes as I am sure they do now.

However, I think that the NJTA should have done at Exit 6 what they did at the Eastern and Western Spur split just north of 14.  Have the three lanes split into 2 for the 6 ramp and 2 through on both carriageways then the the 2 through lanes merge into the 3 continuing lanes, as well as the 2 ramp lanes merge into the 3 Penn Extension lanes.

You figure that set up is working at the transition of the dual carriageways from the Inner and outer to the two spurs, that the engineers would have copied that design instead of making the Exit 6 like any other interchange along the dual configuration.

[myosh_tino]

Southbound San Tomas Expressway in Santa Clara... https://goo.gl/maps/r29KxSh1ihL2

In this case, there are 4 lanes and the two middle lanes merge into a single lane.  The reason why is because the far right lane is an HOV lane (typical for Santa Clara county's expressways).

[jeffandnicole]

Better than the original end of the Truck and Bus Lanes at Exit 9 where all three lanes dropped completely before the extension to 8A took place.  At least the truck lanes afterwards had continuous lanes as I am sure they do now.

However, I think that the NJTA should have done at Exit 6 what they did at the Eastern and Western Spur split just north of 14.  Have the three lanes split into 2 for the 6 ramp and 2 through on both carriageways then the the 2 through lanes merge into the 3 continuing lanes, as well as the 2 ramp lanes merge into the 3 Penn Extension lanes.

You figure that set up is working at the transition of the dual carriageways from the Inner and outer to the two spurs, that the engineers would have copied that design instead of making the Exit 6 like any other interchange along the dual configuration.

I remember attending a meeting before the project first started.  They said numerous studies showed that what they did at Exit 6, both for the merge and diverge, was the optimal way to go.

[Ned Weasel]

Southbound San Tomas Expressway in Santa Clara... https://goo.gl/maps/r29KxSh1ihL2

In this case, there are 4 lanes and the two middle lanes merge into a single lane.  The reason why is because the far right lane is an HOV lane (typical for Santa Clara county's expressways).

Well, son of a gun, it does exist!  I have to wonder, though, is this really the best way to end a lane there?  I can think of three alternatives: (1) end the left lane and then shift the remaining three lanes to the left; (2) exchange the width of the right shoulder for a hard barrier between the HOV lane and the left three lanes, and run the barrier from a point before the lane termination to a point after the lane has fully terminated; or (3) drop the far-left lane as a left-turn-only lane at the preceding intersection (this is probably the least desirable option in terms of maximizing traffic capacity within the available space).  But maybe the present configuration works just fine and drivers handle it in a safe and efficient manner.  Notice the odd signs informing motorists of the merge, though!

[roadman65]

Better than the original end of the Truck and Bus Lanes at Exit 9 where all three lanes dropped completely before the extension to 8A took place.  At least the truck lanes afterwards had continuous lanes as I am sure they do now.

However, I think that the NJTA should have done at Exit 6 what they did at the Eastern and Western Spur split just north of 14.  Have the three lanes split into 2 for the 6 ramp and 2 through on both carriageways then the the 2 through lanes merge into the 3 continuing lanes, as well as the 2 ramp lanes merge into the 3 Penn Extension lanes.

You figure that set up is working at the transition of the dual carriageways from the Inner and outer to the two spurs, that the engineers would have copied that design instead of making the Exit 6 like any other interchange along the dual configuration.

I remember attending a meeting before the project first started.  They said numerous studies showed that what they did at Exit 6, both for the merge and diverge, was the optimal way to go.

You know FDOT here in Orlando did something similar like the truck lanes end before 1991 when it narrowed just south of NJ 18.  When John Young Parkway was extended into FL 434, all the lanes of S Bound FL 423 now require you to merge into one lane then the lane drops, and then another lane drops.  To stay on FL 423 from Lee Road to JYP you must merge over into the lanes of the new JYP extension that keeps two but one of its three S Bound lanes.  No more continuous lanes along FL 423 at John Young and Lee Road.

[peterj920]

Where the Kennedy and Edens Expressways merge together in Chicago.  6 lanes merge to 4, and the center lanes merge.  Here's the sign.

https://www.google.com/maps/@41.9611312,-87.7439025,3a,75y,145.37h,76.99t/data=!3m6!1e1!3m4!1slFA80JNL9hN9qRWDYM4jxw!2e0!7i13312!8i6656?hl=en

Traffic backs up frequently at this merger.

[myosh_tino]

Southbound San Tomas Expressway in Santa Clara... https://goo.gl/maps/r29KxSh1ihL2

In this case, there are 4 lanes and the two middle lanes merge into a single lane.  The reason why is because the far right lane is an HOV lane (typical for Santa Clara county's expressways).

Well, son of a gun, it does exist!  I have to wonder, though, is this really the best way to end a lane there?  I can think of three alternatives: (1) end the left lane and then shift the remaining three lanes to the left; (2) exchange the width of the right shoulder for a hard barrier between the HOV lane and the left three lanes, and run the barrier from a point before the lane termination to a point after the lane has fully terminated; or (3) drop the far-left lane as a left-turn-only lane at the preceding intersection (this is probably the least desirable option in terms of maximizing traffic capacity within the available space).  But maybe the present configuration works just fine and drivers handle it in a safe and efficient manner.  Notice the odd signs informing motorists of the merge, though!

I probably would have opted for (1) to avoid this unusual situation.  (2) might make some sense but having a hard barrier does present some safety issues and would require the placement of sand barrels at the start of the barrier to prevent cars from hitting it head-on.  (3) wouldn't work given the amount of traffic San Tomas handles on a daily basis at that intersection.

I seem to recall that the county wants to add another lane to San Tomas south of El Camino but funding is an issue.

[Rothman]

End of NY 85 westbound freeway section at the bridge over the thruway.  Center lane disappears.  Can be messy at times.

[vdeane]

I believe the "right" lane there is the acceleration lane from Krumkill Rd.  The other two are supposed to merge into each other.

[cl94]

End of NY 85 westbound freeway section at the bridge over the thruway.  Center lane disappears.  Can be messy at times.

I believe the "right" lane there is the acceleration lane from Krumkill Rd.  The other two are supposed to merge into each other.

It's more that the left and right lanes both end, at least that's how it was striped the last time I was through there. It's only messy because it drops 2 lanes at once.

[Rothman]

End of NY 85 westbound freeway section at the bridge over the thruway.  Center lane disappears.  Can be messy at times.

I believe the "right" lane there is the acceleration lane from Krumkill Rd.  The other two are supposed to merge into each other.

It's more that the left and right lanes both end, at least that's how it was striped the last time I was through there. It's only messy because it drops 2 lanes at once.

*nods*

[shadyjay]

New Hampshire has this interesting configuration, pictured is where I-93 NB meets the Everett Tpke just north of Manchester:

https://www.google.com/maps/@43.056154,-71.4711448,3a,75y,16.4h,52.7t/data=!3m6!1e1!3m4!1sP7Gu1erRejMSxPku3wmx1A!2e0!7i13312!8i6656

Three lanes of I-93 meet 2 lanes of the Everett.  However, the right lane of the Everett and the left lane of I-93 merge into each other without any lane lines whatsoever.  So the green car and the grey truck are actually in the same lane.

[adt1982]

On I-55 southbound at the 55/72/6th street interchange in Springfield, IL, the right lane of 55 and the left lane of the 6th street on ramp merge into one lane.

https://www.google.com/maps/@39.7357225,-89.6442704,74m/data=!3m1!1e3

[GaryV]

Are we talking about center merges here?  There's one at the north (east) end of I-196 where it merges into I-96 on the east side of Grand Rapids.

But I thought this thread was intended to be about just losing a lane, not at a merge.

[vdeane]

But I thought this thread was intended to be about just losing a lane, not at a merge.

Ditto.

[shadyjay]

Sorry.. my mistake. 

[cl94]

But I thought this thread was intended to be about just losing a lane, not at a merge.

Ditto.

In many ways, a merge is worse than a lane just ending because neither lane has clear priority. While the Green Book includes standards for such a setup, it is explicitly stated that such a situation is less than ideal and should be avoided.