Multiple Lanes Ending Consecutively

[jeffandnicole]

When has "traffic isn't going too fast" ever been an excuse to construct unsafe roads?

This happens a lot with toll booths.  Look at this.  Or this.  Both former toll booth locations (the latter to funnel all traffic through the booths).  It's also the reason why most freeways in Canada that end at the border have at-grades just north of it - the Canadians don't see the need to construct a full freeway all the way because traffic stops for customs anyways.

And how about where five lanes suddenly converge into two lanes immediately past a toll booth?

Or where six lanes suddenly converge into two lanes?

These don't seem to be a problem, even without yield signs.

Ben Franklin Bridge in Camden: 13 lanes into 2, 3 or 4 lanes, depending on the number of lanes open on the bridge.

NJ Turnpike Exit 1: 14 lanes ultimately narrow down to 1 lane!
https://maps.app.goo.gl/5iwHFQRkahBzdjXR6

[interstatefan990]

In the US there are numerous approvals when it comes to engineering and funding. The governments are usually protected against lawsuits on these type instances. So it's not really as cut and dry as you're making it out to be.

That's why I said they could be held liable. Never said it was a certainty.

And how about where five lanes suddenly converge into two lanes immediately past a toll booth?

Or where six lanes suddenly converge into two lanes?

These don't seem to be a problem, even without yield signs.

Ben Franklin Bridge in Camden: 13 lanes into 2, 3 or 4 lanes, depending on the number of lanes open on the bridge.

NJ Turnpike Exit 1: 14 lanes ultimately narrow down to 1 lane!
https://maps.app.goo.gl/5iwHFQRkahBzdjXR6

No. The one I was referring to, in the first one that vdeane linked, the lane lines were still marked, so vehicles following those lines (aka the law) would unreasonably conflict with other vehicles. Yes, obviously at toll booths many lanes converge into few, but the line markings disappear, giving drivers more leeway and also more responsibility to get into formation again before continuing on the road. Also, it's a former toll booth, so of course it has proper ROW signage, but if you look at the old GSV there are still yield signs, so it's always been that way.

[webny99]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

[fwydriver405]

Apologies for posting about a video game, but you guys should see the hilarious merge lanes in Grand Theft Auto 5:

Real-life example that I've driven through several times

Another real life example I have to drive thru on a near-daily basis in Boston (DCR) - this is coming off of Soldiers Field Rd (SFR) westbound in Boston to get to the Eliot Bridge WB to Gerrys Landing Rd (to get to Watertown and points on Route 2/3).

Two lanes coming off SFR WB to exit onto Eliot Br - only for both to merge into the right lane from SFR EB.

What makes it even more fun, is if you want to hop on Fresh Pond Pkwy or Mt Auburn St from Eliot Br, from that ramp at the Greenough intersection, you have to stay in the far left lane to turn right, and then merge with traffic from Greenough Blvd EB. Otherwise, if you turn right using the far right lane instead of the thru-right lane, you must immediately merge left after turning from the Greenough intersection (the same lane from the thru-right lane mentioned above), otherwise, you end up back on Memorial Drive EB...

See the route of what I mean above.

[ElishaGOtis]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

According to the FHWA, these "ghost island" / "tiger tail" merge configurations could reduce exit delays by up to 80%   
https://www.fhwa.dot.gov/publications/research/operations/20008/index.cfm

[Rothman]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

See the new merge at I-81 SB/I-481 SB (to be BL 81 SB/I-81 SB)... ;D

[ElishaGOtis]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

See the new merge at I-81 SB/I-481 SB (to be BL 81 SB/I-81 SB)... ;D

Which one?

[Rothman]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

See the new merge at I-81 SB/I-481 SB (to be BL 81 SB/I-81 SB)... ;D

Which one?

Southern interchange.

[vdeane]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

See the new merge at I-81 SB/I-481 SB (to be BL 81 SB/I-81 SB)... ;D

Which one?

Southern interchange.

Am I missing something?  I don't believe that matches what is being described from the UK example.

[Rothman]

I think this has been brought up before, but I'm not entirely sure. Is there an official name for this slip road join configuration where one lane splits off and joins the main carriageway, then the next lane joins? What is the benefit of this versus either ending the lane early on the slip road, or a standard taper? There's a ton of these I found in the UK.

It seems to make sense to me in that the "faster" of the two lanes (left here, right in UK) merges into the mainline first, giving more time for slower vehicles in the outer lane to match the speed of the mainline. While the US "double parallel" method allows for the same, the UK "double taper" method somewhat forces the proper behavior instead of allowing "anything goes."

Yeah, this is probably the most awesome one of all:

• Multi-lane entrance ramps merge into the mainline one lane at a time instead of one merging into the other first. This is the functional equivalent of an option lane in reverse, which spreads out the merge and keeps traffic balanced between the lanes instead of crowding the inside lane.

Bit of a bump here, but just wanted to share this here for those that might not follow the UK Roads thread:
The UK uses a unique and IMO superior style of merge for multi-lane entrance ramps - see here and here for examples. It looks a little weird at first but works way better in practice than one ramp lane merging into the other.

See the new merge at I-81 SB/I-481 SB (to be BL 81 SB/I-81 SB)... ;D

Which one?

Southern interchange.

Am I missing something?  I don't believe that matches what is being described from the UK example.

Meh, BL 81 merges into I-81 with two consecutive right lane drops.

[Scott5114]

Real-life example that I've driven through several times

I like the overhead sign just upstream that appears to thank me for preferring roads and bridges. Coahuila apparently hates train foamers and ferry geeks.

[kphoger]

I like the overhead sign just upstream that appears to thank me for preferring roads and bridges. Coahuila apparently hates train foamers and ferry geeks.

I'm not sure if you're joking and know the real answer, or if you really don't know.  So here goes.

Most toll roads in Mexico are managed by CAPUFE, which stands for Federal Roads & Bridges (Caminos y Puntes Federales) and is a division of the SCT (or SICT, if you're hip to the new name, which I'm not yet).  The overhead sign you mentioned is is at the end of a toll road, where it and the free road come back together again for the remainder of the trip into Saltillo.  The sign is thanking you for choosing (preferring) to use the toll road.  And it signs its name at the bottom of the sign:  Sincerely yours, Roads & Bridges.

Back at the other end of the toll road, where you first chose (preferred) to use the toll road instead of the free road, you were greeted with this friendly welcome sign.

[webny99]

Am I missing something?  I don't believe that matches what is being described from the UK example.

Meh, BL 81 merges into I-81 with two consecutive right lane drops.

Just keep driving south: the I-88 merge into I-81 SB is functionally very similar to the UK style merge (except the outside lane becomes exit only instead of merging).

[vdeane]

Just keep driving south: the I-88 merge into I-81 SB is functionally very similar to the UK style merge (except the outside lane becomes exit only instead of merging).

I think of that one as a variant of the GTA example, just with the right lane becoming an exit only lane.  The left lane is essentially an inverse option lane, with no merge room of its own - traffic must do a zipper merge immediately.

[fwydriver405]

Am I missing something?  I don't believe that matches what is being described from the UK example.

Meh, BL 81 merges into I-81 with two consecutive right lane drops.

Just keep driving south: the I-88 merge into I-81 SB is functionally very similar to the UK style merge (except the outside lane becomes exit only instead of merging).

I'd say that's more of an interior lane merge situation rather than the UK-style merge, something akin to this in Amesbury, MA at I-495's northern terminus at I-95.

While we're on the topic on that last thread I linked, there is this example in Peabody, where the right lane of traffic that just exited off of I-95 is ending while US 1 traffic is also "adding" a lane here...

[Scott5114]

I like the overhead sign just upstream that appears to thank me for preferring roads and bridges. Coahuila apparently hates train foamers and ferry geeks.

I'm not sure if you're joking and know the real answer, or if you really don't know.  So here goes.

Most toll roads in Mexico are managed by CAPUFE, which stands for Federal Roads & Bridges (Caminos y Puntes Federales) and is a division of the SCT (or SICT, if you're hip to the new name, which I'm not yet).  The overhead sign you mentioned is is at the end of a toll road, where it and the free road come back together again for the remainder of the trip into Saltillo.  The sign is thanking you for choosing (preferring) to use the toll road.  And it signs its name at the bottom of the sign:  Sincerely yours, Roads & Bridges.

Back at the other end of the toll road, where you first chose (preferred) to use the toll road instead of the free road, you were greeted with this friendly welcome sign.

I figured it was something like that from the context, but given how generic the name is, I thought it was funny.

[ElishaGOtis]

Am I missing something?  I don't believe that matches what is being described from the UK example.

Meh, BL 81 merges into I-81 with two consecutive right lane drops.

Just keep driving south: the I-88 merge into I-81 SB is functionally very similar to the UK style merge (except the outside lane becomes exit only instead of merging).

I'd say that's more of an interior lane merge situation rather than the UK-style merge, something akin to this in Amesbury, MA at I-495's northern terminus at I-95.

While we're on the topic on that last thread I linked, there is this example in Peabody, where the right lane of traffic that just exited off of I-95 is ending while US 1 traffic is also "adding" a lane here...

Immediately north of there, the on ramp to I-95 NB would be the PERFECT place for a UK-style ghost island merge imho https://maps.app.goo.gl/MBi6dgYpctgPnw3c6?g_st=ic

I still can't believe there are only about 2-ish pure definition examples in the USA despite the benefits... is anyone aware of any more other than the one in NJ and the one in TX?

I don't use like to use the word overpowered much when it comes to roadway designs, but when I went to use the one in NJ last week, DANG was it OP

(Technically more if you count intersection-related condition, but not really...
Or this: https://maps.app.goo.gl/bhZhu8HZiraZ8fbg8?g_st=ic )

[SkyPesos]

I-74 EB just east of the eastern I-465 interchange: two right lanes ending. The rightmost lane (first lane that ends) is the one I-74 EB through traffic uses when leaving the I-465 concurrency, and the second to right lane comes from I-465 SB. So the two lanes that don't end here are the two least important lanes.

[webny99]

This merge from Eastport Dr onto the QEW in Hamilton, ON is one of the most literal examples you'll ever see. The inside lane starts ending before the outside lane fully ends. It even looks jarring from a distance.

[dantheman]

On I-195 EB at MA 140 in New Bedford, MA, the onramp from 140 NB merges into the right lane just as the right lane itself ends. https://maps.app.goo.gl/uvKMospXWKCM9kc76

The opposite direction, where 2 lanes widen to 3 + the deceleration lane for the 140 NB exit, looks like the above example on the QEW in reverse... the lane markings are awkwardly painted so that at one point, there's about a half-width deceleration lane plus a one-and-a-half-width right lane that's about to split in two.

[interstatefan990]

Another real life example I have to drive thru on a near-daily basis in Boston (DCR) - this is coming off of Soldiers Field Rd (SFR) westbound in Boston to get to the Eliot Bridge WB to Gerrys Landing Rd (to get to Watertown and points on Route 2/3).

Geez, not even a yellow diamond merge sign? And then you have this added to the equation...