Slip lanes with stop signs

[tolbs17]

We really need some of those here,

https://www.google.com/maps/@35.5909846,-77.3782451,3a,75y,266.09h,88.82t/data=!3m6!1e1!3m4!1sWKrk47xEcghFqLyM-jFiMQ!2e0!7i13312!8i6656

Because look at this. I'm sure slip lanes with stop signs will do for this intersection! This one is clogged.

Yield signs would work better on this one.

SM-G965U

Or a sign that says "Stop here on red"! There was one in Goldsboro that got removed for unknown reasons.

2009
https://www.google.com/maps/@35.3981809,-78.0072356,3a,75y,42.28h,86.92t/data=!3m6!1e1!3m4!1scNSXNIXLcmQJasfwlQS9ww!2e0!7i3328!8i1664

2016
https://www.google.com/maps/@35.3980624,-78.0074131,3a,75y,31.85h,86.25t/data=!3m6!1e1!3m4!1sjr9lQy3T-ILaJbmbM_z3Kg!2e0!7i13312!8i6656

[tolbs17]

Any reasons why that was removed?

[jakeroot]

Any reasons why that was removed?

Why what?

[tolbs17]

Any reasons why that was removed?

Why what?

The last post I posted. Why the slip lane was removed.

[jakeroot]

Any reasons why that was removed?

Why what?

The last post I posted. Why the slip lane was removed.

Jesus, what made you ask now?

Slip lanes are usually removed because of pedestrian concerns. Whether it makes a difference or not is debatable.

[tolbs17]

Any reasons why that was removed?

Why what?

The last post I posted. Why the slip lane was removed.

Jesus, what made you ask now?

Slip lanes are usually removed because of pedestrian concerns. Whether it makes a difference or not is debatable.

Just curious, lol

[JKRhodes]

This one in Tucson, AZ is pretty gross:
https://www.google.com/maps/@32.1900319,-110.90553,3a,49.8y,97.4h,86.01t/data=!3m6!1e1!3m4!1srvtl6c8N7DzSZyx8Pl-a0g!2e0!7i13312!8i6656

Jesus, no kidding. All that room and that was the best setup they could come up with? Tucson normally has my admiration, but they lost a tiny bit here.

Knowing Arizona drivers, I get the feeling that stop sign is barely acknowledged.

I think it's especially bad because the ramp parallels the through lanes for so long.  By the time you reach the actual merge point, if you haven't yet figured out how to merge between two vehicles, you need your license revoked anyway.

Given the vertical curbs and lack of shoulder space downstream of the merge, I am almost certain the standards at the time this road was built warranted the placement of a STOP sign instead of YIELD.

Honestly given the AADT on this portion of Aviation Parkway, it would make sense to either trap the right eastbound lane at the Alvernon exit, or drop the lane prior to this on-ramp and let the entrance ramp utilize the space, since that right lane goes away and the whole thing merges onto Golf Links Road just a few hundred yards downstream anyway.

Then you have this setup on the other side of the same interchange, controlled with a YIELD sign and complete with business driveways to contend with. Needless to say the whole area's kind of messy as far as access control goes.
https://goo.gl/maps/og6p7qFQYoWajP8E7

Elsewhere in Tucson, the right turn at Wilmot and Speedway is controlled with a slip lane and stop signs:
https://goo.gl/maps/zhGP2DuXCkFDin9X8

Golf Links at Houghton:
https://goo.gl/maps/F7rjMF7q1eC4kSnn6

I'm sure there's plenty of other examples throughout the city, though none come to mind. They used to have stop signs at 22nd and Alvernon, finally replaced with YIELD signs several years ago.

[tolbs17]

Apology if this has been posted already, but here's one

https://www.google.com/maps/@35.1542903,-80.8483677,3a,75y,47.71h,76.65t/data=!3m6!1e1!3m4!1sh4jLayaBxdCHMISYOqzHTw!2e0!7i16384!8i8192

Although I don't really like how they made this intersection really.

[jakeroot]

Apology if this has been posted already, but here's one

https://www.google.com/maps/@35.1542903,-80.8483677,3a,75y,47.71h,76.65t/data=!3m6!1e1!3m4!1sh4jLayaBxdCHMISYOqzHTw!2e0!7i16384!8i8192

Although I don't really like how they made this intersection really.

Not posted yet that I can tell.

They could have likely kept that as a yield by reducing the size of the gore area. Painting it in the WA/CA style could have drastically increased the merge area.

[JoePCool14]

Apology if this has been posted already, but here's one

https://www.google.com/maps/@35.1542903,-80.8483677,3a,75y,47.71h,76.65t/data=!3m6!1e1!3m4!1sh4jLayaBxdCHMISYOqzHTw!2e0!7i16384!8i8192

Although I don't really like how they made this intersection really.

Neither do I. That should absolutely be a yield sign there. An accident is waiting to happen from someone not expecting to have to stop.

[jakeroot]

That should absolutely be a yield sign there. An accident is waiting to happen from someone not expecting to have to stop.

It does highlight the odd ways that municipalities approach slip lanes.

For example: quite a few examples in this thread resemble a merge (like the above North Carolina example) rather than a traditional slip lane. You would think these would be more likely to be a yield, yet they end up as stop signs.

I suspect this is because slip lanes that are more like a merge are (surprise, surprise) more likely to encourage drivers to actually merge rather than yield, as is the case at a traditional slip lane (where you stop right at the edge and wait for a gap as necessary). There's nothing wrong with a merge, unless there's no merge area. And even then, it's only a problem if drivers consistently try to merge regardless of whether a gap exists or not.

Basically: slip lanes with no merge area and excellent visibility likely have much higher rates of successful yielding than a half-assed merge area.

[zachary_amaryllis]

this is the intersection i mentioned earlier in the thread (slow link at home).

https://goo.gl/maps/GeDn9QPLP6zXjTLs9

[jakeroot]

this is the intersection i mentioned earlier in the thread (slow link at home).

https://goo.gl/maps/GeDn9QPLP6zXjTLs9

I feel like that stop sign would normally be a yield sign, but was kept as a stop sign because the old intersection (that only had slip lanes in two corners) used a stop sign there as well. The other slip lane was changed to yield sign likely because it was substantially rebuilt enough for them to reconsider the type of control.

But I'm no engineer. That's entirely a guess. Even in situations of high speed limits or even low visibility, it seems like most slip lanes are still yields.

[zachary_amaryllis]

this is the intersection i mentioned earlier in the thread (slow link at home).

https://goo.gl/maps/GeDn9QPLP6zXjTLs9

I feel like that stop sign would normally be a yield sign, but was kept as a stop sign because the old intersection (that only had slip lanes in two corners) used a stop sign there as well. The other slip lane was changed to yield sign likely because it was substantially rebuilt enough for them to reconsider the type of control.

But I'm no engineer. That's entirely a guess. Even in situations of high speed limits or even low visibility, it seems like most slip lanes are still yields.

i actually posted this to the wrong thread.. was supposed to go to 'things that need to be signaized' or something like that.

regardless... that intersection is a deathtrap.

[tolbs17]

Or they can put a signal that says "Stop here on Red".

[jakeroot]

Or they can put a signal that says "Stop here on Red".

Kind of a redundant sign, honestly, unless the stop line is in a weird spot.

Also remember that "stop here on red" is not a substitute for "no turn on red". They both mean what they say, but the former still allows turns on red.

[tolbs17]

Or they can put a signal that says "Stop here on Red".

Kind of a redundant sign, honestly, unless the stop line is in a weird spot.

Also remember that "stop here on red" is not a substitute for "no turn on red". They both mean what they say, but the former still allows turns on red.

Normally those are used if there are MANY cars using that lane. Ramp meters have them and they are activated only at certain times of the day.

How is this one and this one different?

The first one looks like that if it's safe, you can go.

Seems like with the second one, you DO have to wait until the light turns green.

[jakeroot]

Or they can put a signal that says "Stop here on Red".

Kind of a redundant sign, honestly, unless the stop line is in a weird spot.

Also remember that "stop here on red" is not a substitute for "no turn on red". They both mean what they say, but the former still allows turns on red.

Normally those are used if there are MANY cars using that lane. Ramp meters have them and they are activated only at certain times of the day.

How is this one and this one different?

The first one looks like that if it's safe, you can go.

Seems like with the second one, you DO have to wait until the light turns green.

I suspect they're common at ramp meters because many ramp meters use stop-line signals, which is quite unusual compared to standard signals which are overhead and usually a few dozen feet ahead of where people stop.

In both of those cases: right on red is likely permitted. It would be easy enough to argue that the overall maneuver is a right turn even if the maneuver beyond the stop line is more of a straight-on movement.

Good example would be this off-ramp in Tacoma, Wash, where the overall maneuver is more straight but 'no turn on red' signs are still utilized. Because drivers are overall turning "right" off the freeway, they may interpret this movement as more of a right turn and will turn on red.

Nearby is this movement which many interpret as more of a straight maneuver than a right turn. I personally will proceed here on red, but others don't. It's like a 50-50 split and I'd love a sign to either confirm or deny my suspicion ("right on red OK after stop" or "no turn on red").

[JKRhodes]

Nearby is this movement which many interpret as more of a straight maneuver than a right turn. I personally will proceed here on red, but others don't. It's like a 50-50 split and I'd love a sign to either confirm or deny my suspicion ("right on red OK after stop" or "no turn on red").

This whole intersection makes me cringe: I don't like the signal poles bolted down at pavement level with no surrounding islands to protect their bases. I'm also not a fan of the slip lane going from Westbound Tacoma Mall to Southbound Steele. If a car, or a truck pulling a trailer turns the tiniest bit wide, they  run the risk of sideswiping through traffic on southbound Steele. At least there's a painted median they can drive over if there's concern about deviating from the turn path. Then you have the second turn lane going from southbound Steel to Tacoma Mall, which leaves any car choosing to queue in it vulnerable to having their right rear bumper smashed.

It seems like it would be very easy to reconfigure the s-e and n-w movements as the obvious primary route, put steele south of the intersection on a road diet, and swing it into a T intersection with tighter curb radii.

[kphoger]

Here's an interesting location where the stoplight is on a curve, and a 'NO TURN ON RED' sign is used for the seemingly straight-through movement.  Technically, the street name changes from Seneca to Central at this intersection, but I don't know if that has anything to do with it.

[Big John]

^^ Could it be that someone was ticketed going through the intersection on red and had the ticket thrown out saying they were making a right turn on red?

[mrsman]

Nearby is this movement which many interpret as more of a straight maneuver than a right turn. I personally will proceed here on red, but others don't. It's like a 50-50 split and I'd love a sign to either confirm or deny my suspicion ("right on red OK after stop" or "no turn on red").

This whole intersection makes me cringe: I don't like the signal poles bolted down at pavement level with no surrounding islands to protect their bases. I'm also not a fan of the slip lane going from Westbound Tacoma Mall to Southbound Steele. If a car, or a truck pulling a trailer turns the tiniest bit wide, they  run the risk of sideswiping through traffic on southbound Steele. At least there's a painted median they can drive over if there's concern about deviating from the turn path. Then you have the second turn lane going from southbound Steel to Tacoma Mall, which leaves any car choosing to queue in it vulnerable to having their right rear bumper smashed.

It seems like it would be very easy to reconfigure the s-e and n-w movements as the obvious primary route, put steele south of the intersection on a road diet, and swing it into a T intersection with tighter curb radii.

Agreed.  Other cringeworthy features that I noticed was that there are ped signals here.  The painted crosswalks have been removed, but it seems like the crosswalks were designed to allow for peds to make some crossings, but the whole intersection seems like a no-man's land, especially where pedestrians are concerned.

southbound Steele has continuous green, so no peds are crossing it.  If you are not going to realign the intersection in the way that JKRhodes recommends, at least put in a RYG signal for southbound Steele so that they have red when traffic turning left from Tacoma mall has the right of way.

THere does seem to be a legal (but insane) way to cross from the southeast corner to the northeast corner (so that you continue on the eastside sidewalk of Steele). 

Cross the slip ramp so that you are in the triangular painted island.  Next use the ped signals to cross the NB Steele traffic to be in the island surrounded by yellow paint.  Make a 90 degree turn to cross thru the center of the intersection (during the phase when Tacoma Mall may turn left onto southbound Steele.) to the white trapezoidal island and finally crossing the two lanes right turn of Tacoma Mall to northbound Steele to reach the sidewalk again.  I cannot fathom how this can be safe in anyone's estimation.

Assuming that the ped crossing is legal, albeit dangerous, it would seem that the last step of the crossing is basically perpendicular to the curving movement of the NB Tacoma Mall to Steele "right turn".  That aspect, indicates to me, that this is more of a straight movement then a right turn, so the movement should not be allowed on red, despite the fact that you are going from Tacoma Mall to Steele.  The name of the street changing should not dictate whether this is a right on red.  It does seem more like the straight movement, IMO.  The fact that the stop line is so far back should also indicate that you cannot go so far forward on red.  THe opportunity to turn onto Steele is so far ahead, that you are actually going straight, not right at the stop line.

There is a similar intersection near me, but they do a few things a little better and there it is clear, despite a right turn from Parklawn to Randolph, the movement is treated as a straight and cannot be made on red.  There is no NTOR sign, because the layout is clear enough that the sign is not required.  It is a straight movement, not a right turn.  I have never seen a car make a right from Parklawn to Randolph on red.

https://www.google.com/maps/@39.0531224,-77.1060242,3a,75y,50.18h,85.12t/data=!3m6!1e1!3m4!1s50G2Oq3I57cr-eZXmPHJXA!2e0!7i16384!8i8192

Regardless, at minimum, as jakeroot has said, they should put up signage to clarify the movment at Steele/Tacoma Mall if it is unclear for drivers.  I recomment NTOR there.

[jakeroot]

clipped

That intersection at Tacoma Mall Blvd / Steele St certainly got a bit more attention than I would have expected. Although retrospectively, I can see why it did.


As far as the pedestrian situation, I actually saw a group of four crossing from the southeast corner to the western edge. I realized a few things when I saw them do this:

(1) although there were crosswalk markings, they have simply faded to being nearly invisible. You can see some of the edges in this GSV shot. I'm not sure why they were not repainted as the newer piano-style markings that Tacoma has been used for almost twenty years. Perhaps they are planning a rethink of this intersection.

(2) The crossings that go to that yellow island are very close to the travel lanes. As you're making that "left turn" from Steele to Tacoma Mall, which can easily be made at 35+, you get very close to pedestrians.

(3) I slowed down to watch them continue. After they crossed to the yellow island, they wanted to continue to the western side of the intersection, but seem confused why they had a signal to cross to the middle but no signal to finish crossing to the far edge. Both southbound lanes had to stop and yield to allow them to finish crossing. There was once a painted crossing here (transverse style as with the others) but was genuinely removed at some point in the last 15 years.


In terms of the traffic flow:

* The awkwardness of having the middle lane split but then immediately have a protected left turn somehow works in practice, but there is the chance of a close call on occasion. Most people end up using the far/outside lane to continue southbound.

* the movement between westbound Tacoma Mall Blvd and northbound Steele may seem more like a straight movement, but in practice, it does feel like more of a right turn. Best reason would be to look at the maneuver from a ways back. At the intersection itself, the movement beyond the stop line feels very straight, but the overall maneuver feels more like a turn, so you end up with that 50-50 stay-go split that I mentioned before.

* the huge neutral area to the north of the intersection results in messes like this. Choosing not to turn on red during high-traffic periods means that you sometimes aren't able to go at all.




As a side-note: I actually redesigned this intersection a while back, but I cannot figure out where I posted it:

[tolbs17]

Why can't they just put a yield sign here?

[SkyPesos]

I drove through this one at KC's Country Club Plaza today.