Innovative, Unique, or Strange Lane Markings

[Revive 755]

On Route 17 past Wilmington, North Carolina on the way to Myrtle Beach, they have a plentiful amount of arrows directing drivers to proceed in the direction they're going.

Like these?  I think NCDOT did this to discourage driving the wrong way in the respective lanes.

[mrsman]

The right turn markings at this junction in Johannesburg, South Africa: https://goo.gl/mGNjmw

I guess lead/lag wasn't an option.

Lead/lag is unlikely an option for this intersection since there are median bus lanes.  (the lanes marked in red).  If the opposing left turns had different signal phases, that would leave little time in the intersection for the bus lanes to go.

For a US example, check out hte Chandler Blvd busway (orange line) in North Hollywood, CA.  There is a similar wide median because of bus lanes (and beforehand trolley cars).  All left turns are protected only and share the same time in the signal.  No special lane markings though.

[vdeane]

There's a lead-lag intersection near where I live, and outside of rush hour, the light intervals are evenly divided between the left turns and the all-straight phase (for the main road; the side road doesn't have an all-straight phase).

[mrsman]

There's a lead-lag intersection near where I live, and outside of rush hour, the light intervals are evenly divided between the left turns and the all-straight phase (for the main road; the side road doesn't have an all-straight phase).

OK.  Let's work on an example to show why lead-lag is especially disadvantageous for a road with median bus lanes.

00 EB green.  EB to NB  green arrow.  WB    red.   WB to SB red arrow.
10 EB green.  EB to NB yellow arrow.   WB    red.  WB to SB red arrow.
13 EB green.  EB to NB      red arrow.   WB    red.  WB to SB red arrow.
15 EB green.  EB to NB        red arrow.    WB green. WB to SB red arrow.

40 EB yellow.  EB to NB       red arrow.   WB green.  WB to SB red arrow.
43 EB red.       EB to NB      red arrow.  WB green.  WB to SB red arrow.
45 EB red.      EB to NB       red arrow.  WB green.  WB to SB green arrow.
55 EB red.      EB to NB  yellow arrow.  WB yellow.  WB to SB yellow arrow.
58 EB red.      EB to NB      red arrow.  WB      red.  WB to SB red arrow. (all-red)

60 N/S green
85 N/S yellow
88 N/S red (all red)
90=00

OK, as you can see, each left turn protected phase has 10 seconds of green arrow, 3 seconds of yellow arrow, and a 2 second red arrow phase for clearance until a different phase is released.  The leading left is followed by westbound traffic.  The lagging left is followd by N/S traffic. 

At the same time, each straight direction on the E/W street has 40 seconds of green and 3 seconds of yellow.  EB from 00-40 green, and 40-43 yellow.  WB from 15-55 green, and 55-58 yellow.  And yes, from 15-40, 25 seconds, both greens overlap and the left turns are prohibited by red arrow.

So straight-through E-W traffic has 40 seconds of green time, but a median bus lane will only have 25 seconds of green time, because neither arrow can be green or yellow at the time when the bus lane has priority.  So here, with a 90 second cycle lenth, buses only get 25 seconds.

Now, let's incorporate having the left turns at the same time, leading lefts.

00 left turns  green arrow.  EB/WB    red.
10 left turns yellow arrow.   EB/WB    red.
13 left turns red arrow.   EB/WB    red.
15 left turns red arrow.   EB/WB    green.

55 left turns red arrow.   EB/WB yellow. 
58 left turns red arrow.   EB/WB      red. 

60 N/S green
85 N/S yellow
88 N/S red (all red)
90=00

OK, as you can see, each left turn protected phase has 10 seconds of green arrow, 3 seconds of yellow arrow, and a 2 second red arrow phase for clearance until a different phase is released.  Same as above.

Each straight direction on the E/W street has 40 seconds of green and 3 seconds of yellow, 15-55 green, and 55-58 yellow.  40 seconds for each direction of travel, including the bus lanes.

So, assuming that we want to give buses some priority, (and that's fair given the provision for bus lanes), the buses will get more green time if the left turn phases overlapped in time and we do not incorporate lead-lag.

Also, I believe that all would agree that we would not  want to incorporate FYAs where there are median bus lanes, because a left turn driver would also have to watch out for buses coming behind them as well as in front of them to make a left turn safely.  I am not aware of any installation of median bus lanes (or light rail/tram etc.) that does not employ protected-only left turns.  [The only exception maybe during late night hours when no buses are run and a rule is in place that no out of service buses can use the bus lanes.]

[jakeroot]

Recent discussion in this thread has reminded me why I prefer shoulder-based BRT/Tram systems (second to elevated systems, though). No turn restrictions with those.

Also, I believe that all would agree that we would not  want to incorporate FYAs where there are median bus lanes, because a left turn driver would also have to watch out for buses coming behind them as well as in front of them to make a left turn safely.  I am not aware of any installation of median bus lanes (or light rail/tram etc.) that does not employ protected-only left turns.  [The only exception maybe during late night hours when no buses are run and a rule is in place that no out of service buses can use the bus lanes.]

I thought that I had found an example a while back, but it turns out I didn't:

This intersection in Cape Town, South Africa has two bus lanes leading into it, but they are turn movements (no straight-ahead movements). Before the cars proceed, the buses perform their turns. After that, the right turns get their green arrows, followed by a permissive right turn phase:

https://goo.gl/euJR56

[thenetwork]

On US-160 WB coming out of Wolf Creek Pass, many of the signs fortruckers have been added as thermal signs embedded in the pavement.  (Truck Speed Limits, Curve Signs some truck regulation signs,...).  Looked like they were just installed within the last month or so.

[Revive 755]

So, assuming that we want to give buses some priority, (and that's fair given the provision for bus lanes), the buses will get more green time if the left turn phases overlapped in time and we do not incorporate lead-lag.

And there are that many buses that need the full 25 seconds, much less a full 25 seconds every single cycle?

Plus the base cycle length of 90 seconds would be on the low side for an urban arterial with signal coordination.

[jakeroot]

Are the hatch/chevron markings along the left edge of one-way roads allowed to be white?

Saw this today in Tacoma, WA. South 14 St at Court A.

[Otto Yamamoto]

Are the hatch/chevron markings along the left edge of one-way roads allowed to be white?

Saw this today in Tacoma, WA. South 14 St at Court A.

Sometimes NYC streets have white marking on the left of a one way street. Up until a couple of years ago, painted reservations had white hatchind.

STV100-2

[roadfro]

Are the hatch/chevron markings along the left edge of one-way roads allowed to be white?

Saw this today in Tacoma, WA. South 14 St at Court A.

Nope, not supposed to be white.

[jakeroot]

Are the hatch/chevron markings along the left edge of one-way roads allowed to be white?

http://i.imgur.com/iDZoHuI.jpg

Sometimes NYC streets have white marking on the left of a one way street. Up until a couple of years ago, painted reservations had white hatchind.

I've seen painted central reservations with white-only markings exactly once: Pennsylvania Ave in DC, between 15 and 3 St SW: https://goo.gl/NN3TRf -- no idea why they did this.

Are the hatch/chevron markings along the left edge of one-way roads allowed to be white?

http://i.imgur.com/iDZoHuI.jpg

Nope, not supposed to be white.

Didn't think so. I thought that, maybe, there was an exception for one-way roads not part of a divided highway system, but I guess not.

[jakeroot]

A strange lack of markings for this double right movement from an off-ramp. In theory, the two lanes are supposed to merge directly into the two through lanes, but the existence of a third left-turn only lane (the destination of many of those exiting the freeway) often results in those in the right lane, exiting the freeway, being able to turn into either of the through lanes.

https://goo.gl/8YfvyX

[MarkF]

On HI 380 in Maui, there are several of these in the shoulder:

first one of these:


followed a hundred or so feet later with one of these:


two somewhat close on a small bridge, but in a reverse pattern:


Anyone seen these before, or know what they signify?  They are only on a stretch where a new concrete roadbed was put in a couple of years ago.

[jakeroot]

Not strictly related to your comments (I'm as dumbfounded as you), but that is a remarkably clear sky in those photographs. I've never been to Hawaii when it wasn't at least partly cloudy, nor have I seen many photos of a completely clear sky.

[Scott5114]

My guess is they are trying to direct something onto or off of the shoulder by following the line. Bicycles, perhaps? It would make sense to divert bicycles into the mainline near an intersection so turns don't conflict with shoulder-riding bicycles. As for the bridge, I'm not sure, but perhaps there's some condition with the shoulder there (i.e. drainage) that makes it safer for bikes to use the mainline there.

Other possibilities include snowplows (not likely in Hawaii) or street sweepers.

[vdeane]

Maybe they're marking the beginning/end of the rumble strips?

[jakeroot]

Maybe they're marking the beginning/end of the rumble strips?

I was thinking so, but the first photo doesn't show any rumble strips on either side of the marking. Unless I just can't make them out.

FWIW, Hawaii does use a lot of markings, some that sometimes seem nonsensical. A lot of the "optional" markings in the MUTCD seem to be used.

[thenetwork]

Maybe they're marking the beginning/end of the rumble strips?

I was thinking so, but the first photo doesn't show any rumble strips on either side of the marking. Unless I just can't make them out.

FWIW, Hawaii does use a lot of markings, some that sometimes seem nonsensical. A lot of the "optional" markings in the MUTCD seem to be used.

And in the middle photo there is a lining marking in the 1:00 position just past the light.  Perhaps "No Stopping/No Parking" zones?

[MarkF]

Not strictly related to your comments (I'm as dumbfounded as you), but that is a remarkably clear sky in those photographs. I've never been to Hawaii when it wasn't at least partly cloudy, nor have I seen many photos of a completely clear sky.

As has been the case every time I've been to Maui, there were clouds around Haleakalā.  Here's another one, right where the concrete pavement starts:

[MarkF]

By the way, I have a video of the complete stretch here:
https://youtu.be/zG9czYgAiD4

Google maps just shows it when the HI 380 roadbed was being updated to concrete.

[kphoger]

A strange lack of markings for this double right movement from an off-ramp. In theory, the two lanes are supposed to merge directly into the two through lanes, but the existence of a third left-turn only lane (the destination of many of those exiting the freeway) often results in those in the right lane, exiting the freeway, being able to turn into either of the through lanes.

https://goo.gl/8YfvyX

I despise all double lane merges like this. 

[jakeroot]

A strange lack of markings for this double right movement from an off-ramp. In theory, the two lanes are supposed to merge directly into the two through lanes, but the existence of a third left-turn only lane (the destination of many of those exiting the freeway) often results in those in the right lane, exiting the freeway, being able to turn into either of the through lanes.

https://goo.gl/8YfvyX

http://i.imgur.com/CsbrWWR.png

I despise all double lane merges like this.

I wouldn't mind them, if they just used some guide lines. They painted one center-line marking right after the stop line, and then gave up.

[Michael]

I saw this 3D crosswalk on Imgur a few days ago.  I think it would cause accidents due to people braking suddenly because they thought they were going to hit it.

[jakeroot]

These waiting lines near Cape Town, ZA indicate to drivers turning right that, at least the right lane, should wait in the path of oncoming traffic.

https://goo.gl/6ZVYpE

[Scott5114]

Cape Town, ZA

Think you might mean SF...