Two Seperate Channelized Rights Turns For Same Movement

[Flint1979]

This is at EB SH 6 at US 283 N of Sayre OK.
https://www.google.com/maps/@35.4068587,-99.6558544,160m/data=!3m1!1e3

That is a strange intersection. Seems like there should be a roundabout there.

[Elm]

In Westminster, CO, there used to be two right turns from eastbound 120th Ave to Federal Blvd (the path of southbound US 287), but it was removed around 2016. It's visible on Historic Aerials; in Google Maps, it's still around on the 3D view, but not on 2D.

Before the double right turn situation, the mainline road through in the area was US 287 (four lanes), following the curved path. Sometime between '71 and '91 (going by Historic Aerials), the roads were rearranged to make 120th & Federal the primary intersection, but a wide right turn was left on the former path of southbound 287. The highway had crossed a creek on that path, and the unused northbound bridge was left in place. Later, when the outer right turn lane was removed, the former northbound bridge was removed, and the southbound bridge was kept to carry a trail over the creek.

Doesn't this just make it harder for traffic exiting 119th Ave turning left? Because now they have to deal with all that traffic coming from US-287 South rather than that traffic being able to come in after the intersection.

Stupid redesign IMHO. The two channelized rights appears to have worked fine. The larger, free-flowing one for US-287 thru traffic, and the smaller one for traffic heading to 119th Ave.

It looks like they added an acceleration lane for left turns from 119th Ave with the intersection project; depending on how people are turning into the southbound lanes, that might be enough to make the turn easier. (I haven't been around there, personally, so I couldn't really say).

The city took the lead on the 120th and Federal intersection project, and it sounds like the open space and trails surrounding that intersection are a big deal for them (reading this); I imagine they took an active interest in repurposing the bridge, and CDOT probably didn't mind handing off responsibility for it, since it wasn't critical for their purposes.

[jakeroot]

I see zero things wrong with the redesign. Seems to have achieved all the goals. Opened up new land for development, slowed down that right turn (a little), created new paths for walking, added a merge lane for 119th traffic...list goes on.

Really no reason for a slip lane to be as long/wide as the original, even if it was left over from the old layout. Props to the involved jurisdictions for a job well-done.

[hotdogPi]

MA 113 at Wheeler Rd. in Dracut

[roadfro]

MA 113 at Wheeler Rd. in Dracut

That is better characterized as one channelized right turn, and a short frontage road serving a farm (which, in the 2012 street view, is marked with "Do Not Enter" signs and blocked with orange construction barrels)

[Rothman]

Yeah, it looks almost like a private driveway.

[MASTERNC]

There is one at the corner of Lenox Road and SR 141 in Buckhead (Atlanta).  Technically it created three right turns lanes (one channelized, the rest signalized).  As of this Google Maps image, though, the channelized lane is blocked for building construction (behind the chainlink fence).  Whether it returns after construction is unknown.

https://www.google.com/maps/@33.8488488,-84.3741054,3a,75y,249.52h,83.31t/data=!3m6!1e1!3m4!1sr2jHprIkdoIAtSWn5fW_vA!2e0!7i16384!8i8192

[freebrickproductions]

I've seen a couple around the Huntsville area:
Memorial Parkway and Airport Road

Bradford Drive and Explorer Boulevard (two here!)

A few "kinda-sorta" ones:
Memorial Parkway and Governors Drive (channelized right turn + right turn at the intersection itself)

Sparkman Drive and Ben Graves Drive (similar to the one above, though technically the second right turn has to be done via two right turns at an intersection)

One of the ramps at Exit 9 on I-565 in Madison also splits into two separate lanes (that get seperated by a median) for the same movement:
Overhead
GSV

[jakeroot]

I've seen a couple around the Huntsville area:
Memorial Parkway and Airport Road

Bradford Drive and Explorer Boulevard (two here!)

I think these are the first of this thread that genuinely meet the criteria of the OP. Two separate channelized right turns, with both movements serving the same traffic. In both examples, there are no movements that occur after the right turn that would dictate the specific use of the "inside" slip lane. Therefore, it's redundant, much like the OP's example (assuming the outer slip lane would being the primary channelized turn).

There's a separate argument to be made for improved traffic flow with a separate slip lane, but that's another matter.

[freebrickproductions]

I've seen a couple around the Huntsville area:
Memorial Parkway and Airport Road

Bradford Drive and Explorer Boulevard (two here!)

I think these are the first of this thread that genuinely meet the criteria of the OP. Two separate channelized right turns, with both movements serving the same traffic. In both examples, there are no movements that occur after the right turn that would dictate the specific use of the "inside" slip lane. Therefore, it's redundant, much like the OP's example (assuming the outer slip lane would being the primary channelized turn).

There's a separate argument to be made for improved traffic flow with a separate slip lane, but that's another matter.

In the case of the first one, I think it's to increase throughput as Westbound Airport -> Northbound Parkway is a pretty major movement there. Most traffic does use the slip lane that doesn't have a yield sign in my experience, but a fair amount of traffic does use the other one.

In the case of the second, I don't really have any idea as to why it was done other than possibly being intended to be the "main entrance" to Cumming's Research Park from Research Park Boulevard.

[mrsman]

I've seen a couple around the Huntsville area:
Memorial Parkway and Airport Road

Bradford Drive and Explorer Boulevard (two here!)

I think these are the first of this thread that genuinely meet the criteria of the OP. Two separate channelized right turns, with both movements serving the same traffic. In both examples, there are no movements that occur after the right turn that would dictate the specific use of the "inside" slip lane. Therefore, it's redundant, much like the OP's example (assuming the outer slip lane would being the primary channelized turn).

There's a separate argument to be made for improved traffic flow with a separate slip lane, but that's another matter.

In the case of the first one, I think it's to increase throughput as Westbound Airport -> Northbound Parkway is a pretty major movement there. Most traffic does use the slip lane that doesn't have a yield sign in my experience, but a fair amount of traffic does use the other one.

In the case of the second, I don't really have any idea as to why it was done other than possibly being intended to be the "main entrance" to Cumming's Research Park from Research Park Boulevard.

These are redundant right turn slip lanes, but there is likely a purpose.  Normally, when you have something like this, it's because traffic that will turn right and then make an immediate left will not be able to do so from the right of those two lanes.  So those people will yield in order to turn right onto the left lane.  The other traffic that will be happy to stay in the right lane upon turning can take the free turn.

Now it's not so obvious if that is at play here because it is entirely possible for someone to take the right turn into the right lane and then merge left.  But I don't know if there are busy periods where such becomes difficult. 

Take a look at this corner:

https://www.google.com/maps/place/Arcola+Ave,+Silver+Spring,+MD+20902/@39.0359093,-77.0266333,226m/data=!3m1!1e3!4m5!3m4!1s0x89b7cf0e5aaa7d87:0x56ae9245c46b8302!8m2!3d39.0370441!4d-77.0262657

Southbound Arcola has a single lane channelized turn onto westbound University Blvd.  For most people who are making the turn, they can make the turn into the right lane and continue down University Blvd and safely merge to the center or left lane if they want.  Due to the traffic signal operations at the Arcola/University intersection, the right lane of University is generally free and open, even if there is traffic coming down the other two lanes.  This is because traffic on the right lane (except buses) must turn right at the intersection just preceding the channelization.  Since buses can continue straight, we have a yield situation and not a free turn into the right lane.  So in other words, when University has the green and the left and center lanes are busy, most people can still make the right turn at the channelization into the right lane without being unimpeded, unless a bus (or somebody who illegally did not make the forced right) is coming in the right lane.  And knowing this, people will honk at you if you hesitate, since they want the opportunity to go.

Yet, there is a pretty major left turn at Sligo Creek Pkwy just to the left of the satellite view screenshot.  During busy times it is quite difficult to make the right turn, two lane changes, and then a left, since there isn't that much space.  So people on Arcola who have intention to turn onto University and then onto Sligo Creek will often wait until traffic is clear on all three lanes before making their right and swinging to the left lane.  This naturally frustrates the people who want to turn onto the right lane of University and just go, especially since the right lane is free.

Now if we had a double channelization like in Huntsville, there would be no problem.  The right lane would be the free turn (again aside from the buses) for those who want University.  The left lane will be for those who want to swing to the left lane and will wait for traffic to clear before making their turn.  Since the two right turns are separated, the people who will make the left onto Sligo will not impede the other right turners.

Now I don't know if the traffic patterns in Huntsville are similar, but I could see that during busy times there could be a similar traffic situation as exists in Silver Spring, MD.  For Explorer/Bradford, the right lane is for the free turn for traffic heading to 255 south.  The left lane is for 255 north and other Bradford traffic who may have to wait for traffic to clear when Bradford traffic has a green light.  These people will not impede the traffic bound for 255 south, because there are two right turn lanes instead of one.

Near me, there is an intersection where we only have one channelized right turn.  Most of the right turn traffic will be fine turning right into the right lane and then driving down the road for a while.  These people can generally complete their turn if the right lane of the street they are turning onto is clear, even if the left lane is full of traffic.  But some of the people would like to make a quick left after making that right turn. 

[roadfro]

Not quite like the OP, but here's one in Nevada: I-15 SB off ramp to St. Rose Pkwy/SR 146

When NDOT rebuilt the St Rose Pkwy interchange in the late-2000s, it was in part because the Southern Highlands development was overloading the interchange with the south end of Southern Highlands Pkwy having been shoehorned into the existing 60's era trumpet.  The ramp is now also signed for Southern Highlands Pkwy–as St. Rose forms the stem of a T intersection with Southern Highlands just west of the new SPUI.

Given the demand for traffic exiting SB I-15, westbound on St Rose and then turning north onto Southern Highlands, NDOT designed a channelized right turn that allows this to be a completely free movement. There is another channelized right turn for the southbound ramp, which allows access to southbound (and also northbound) Southern Highlands Pkwy.

[jakeroot]

Given the demand for traffic exiting SB I-15, westbound on St Rose and then turning north onto Southern Highlands, NDOT designed a channelized right turn that allows this to be a completely free movement. There is another channelized right turn for the southbound ramp, which allows access to southbound (and also northbound) Southern Highlands Pkwy.

Looks like the interchange was built a while ago; any idea if they planned specific upgrades to that old trumpet interchange, before dumping that whole configuration for a SPUI? I always find it interesting when interchanges are rebuilt in such a way, that any old configurations are virtually unrecognizable. In WA, it's pretty unusual to see a total rebuild. WSDOT's new planning style generally dictates "spot" improvements unless a total rebuild is absolutely necessary. For instance, rebuilding a diamond into a DDI, or converting a cloverleaf into a parclo.

I can think of a few specific improvements to that old interchange that may not have necessitated a total rebuild, but I appreciate that the SPUI opened up new land.

Off-topic: props to NDOT for putting in a signalized crossing for that NB 15 Fwy movement.

[roadfro]

Given the demand for traffic exiting SB I-15, westbound on St Rose and then turning north onto Southern Highlands, NDOT designed a channelized right turn that allows this to be a completely free movement. There is another channelized right turn for the southbound ramp, which allows access to southbound (and also northbound) Southern Highlands Pkwy.

Looks like the interchange was built a while ago; any idea if they planned specific upgrades to that old trumpet interchange, before dumping that whole configuration for a SPUI? I always find it interesting when interchanges are rebuilt in such a way, that any old configurations are virtually unrecognizable. In WA, it's pretty unusual to see a total rebuild. WSDOT's new planning style generally dictates "spot" improvements unless a total rebuild is absolutely necessary. For instance, rebuilding a diamond into a DDI, or converting a cloverleaf into a parclo.

I can think of a few specific improvements to that old interchange that may not have necessitated a total rebuild, but I appreciate that the SPUI opened up new land.

Off-topic: props to NDOT for putting in a signalized crossing for that NB 15 Fwy movement.

To my knowledge, NDOT didn't plan any upgrades to the trumpet other than its complete rebuild into a SPUI. The only upgrade that ever happened was the tie-in of Southern Highlands Pkwy into the loop end of the trumpet.

As late as 2003, this west end of SR 146/St Rose Pkwy was still two-lane highway, and overburdened by increasing traffic and residential developments from multiple directions–Southern Highlands to the west, the city of Henderson's continued westward expansion from areas like Seven Hills, and unincorporated county neighborhoods pushing further south. At the time, this was the only I-15 interchange in the area; the SR 160/Blue Diamond Road about 6 miles north was the next closest in town (and was also overburdened). In 2003, NDOT was getting ready to commence construction to widen SR 146 to its current eight-lane configuration between Eastern Avenue and Las Vegas Boulevard (I interned with NDOT that summer and did a bit of survey work on that project). The I-15 SPUI was the final phase for SR 146 improvements–a rebuild was really necessary given the tie-in to other improvements and traffic.