Dual left turn only signs outside of California

[blawp]

Worse strategies, generally. Such as...how can I save the most money while complying with the bare minimum requirements of the MUTCD.

[Brandon]

Worse strategies, generally. Such as...how can I save the most money while complying with the bare minimum requirements of the MUTCD.

No, different strategies.  Illinois, for example, uses two left turn signals minimum regardless of number of turn lanes.  There is always a side mounted signal, and a minimum of three signals per direction.

Personally, I thought the number of protected only left turns in California was nuts.  We used a lot of protected/permitted lefts here in Illinois, which, IMHO, is superior to what CalTrans uses.  And, personally, I think the clearing left turns used by MDOT (Michigan) are even better than that for traffic flow.  But, of course, you don't need to worry about left turn signals when you don't have them on the biggest of roads such as Telegraph and Eight Mile. 

[DaBigE]

On the far side of the intersection it hangs.

Unless it's a T-intersection, you still have oncoming traffic that will pass under it (the opposing left turn or thru movement), and potentially the sloppy left turn movement from the cross-street.  If you're going to mount the signal that low, you might as well go with a pedestal mount.  If mounting the signal ~4-ft lower, why not simplify the arm and mount them all at the same level?  IMO, this just looks sloppy.

[blawp]

Pedestal mounts in the median tend to get clobbered by cars.

[blawp]

Worse strategies, generally. Such as...how can I save the most money while complying with the bare minimum requirements of the MUTCD.

No, different strategies.  Illinois, for example, uses two left turn signals minimum regardless of number of turn lanes.  There is always a side mounted signal, and a minimum of three signals per direction.

Personally, I thought the number of protected only left turns in California was nuts.  We used a lot of protected/permitted lefts here in Illinois, which, IMHO, is superior to what CalTrans uses.  And, personally, I think the clearing left turns used by MDOT (Michigan) are even better than that for traffic flow.  But, of course, you don't need to worry about left turn signals when you don't have them on the biggest of roads such as Telegraph and Eight Mile. 

Caltrans' statewide standard loop detection setup ensures motorists never wait too long for the arrow to change.

[DaBigE]

Pedestal mounts in the median tend to get clobbered by cars.

Okay and so do mailboxes, and that is what insurance companies are for.  It still does not answer my height clearance question.  Nor does it give rationale for not mounting them all in the same relative level.

[myosh_tino]

There are several of these mast arms here in Salinas. I don't know about elsewhere.

I remember seeing these types of mast arms in the Sacramento area but not so much in the greater San Francisco Bay Area.  I think these types of mast arms were developed to avoid having to mount a left turn signal in the middle of the street on an island and/or median.  I don't know of any newer installations of this type of mast arm as the cities have gone to using a longer spanning mast arm and eliminating the island-mount signal (presumably because they tend to get knocked over and have to be replaced).

EDIT: Found some photos (actually GSV images) of some of the same type of mast arms both from the Sacramento area...

[Brandon]

Worse strategies, generally. Such as...how can I save the most money while complying with the bare minimum requirements of the MUTCD.

No, different strategies.  Illinois, for example, uses two left turn signals minimum regardless of number of turn lanes.  There is always a side mounted signal, and a minimum of three signals per direction.

Personally, I thought the number of protected only left turns in California was nuts.  We used a lot of protected/permitted lefts here in Illinois, which, IMHO, is superior to what CalTrans uses.  And, personally, I think the clearing left turns used by MDOT (Michigan) are even better than that for traffic flow.  But, of course, you don't need to worry about left turn signals when you don't have them on the biggest of roads such as Telegraph and Eight Mile. 

Caltrans' statewide standard loop detection setup ensures motorists never wait too long for the arrow to change.

We use one of two, either the loop (can get covered by ice and snow) or the infrared detector mounted on the mastarm (can be blocked by weather).  The loop may not always detect a motorcycle whereas the detector can.

[myosh_tino]

We use one of two, either the loop (can get covered by ice and snow) or the infrared detector mounted on the mastarm (can be blocked by weather).  The loop may not always detect a motorcycle whereas the detector can.

IIRC, the loop detectors around here can sense a motorcycle and some cities have installed loop detectors in the bike lane to allow cyclists to be able to trigger the signal.  Snow and ice isn't a problem in 2/3 of the state (which includes all of the major metropolitan areas).

[blawp]

Always attacking California...

[blawp]

Pedestal mounts in the median tend to get clobbered by cars.

Okay and so do mailboxes, and that is what insurance companies are for.  It still does not answer my height clearance question.  Nor does it give rationale for not mounting them all in the same relative level.

Insurance is costly on a routine event... In any case, I already explained to you that left turns are low-speed approaches, where the signal shall be most visible and closest to the car at the front of the line. Thru traffic is typically a high speed approach where the signal has to be visible to traffic well upstream of the intersection.

[DaBigE]

That left turn signal still doesn't look like it has enough clearance...maybe 12-ft?  Does the extra ~4-ft really make that much of a difference in visibility?

Insurance is costly on a routine event... In any case, I already explained to you that left turns are low-speed approaches, where the signal shall be most visible and closest to the car at the front of the line. Thru traffic is typically a high speed approach where the signal has to be visible to traffic well upstream of the intersection.

Speed of the approach has NOTHING to do with VERTICAL CLEARANCE.  That has been my question/concern all along; tall vehicles being able to pass underneath. 

Regardless, upstream visibility shouldn't be that much of a concern as a vehicle should not and cannot be taking the left turn at the posted speed limit anyway.  If there is a concern with the first vehicle seeing the signal, you can either a) adjust the vertical angle of the suspended signal, or b) mount a supplementary signal on the far-left side, as many other states (including CA) do already.  For the record, I never mentioned a median-mounted pedestal signal.

[blawp]

If you're going to mount the signal that low, you might as well go with a pedestal mount.

revisionist history, folks.

[myosh_tino]

That left turn signal still doesn't look like it has enough clearance...maybe 12-ft?  Does the extra ~4-ft really make that much of a difference in visibility?

Not wanting to sound like a smart-ass but don't you think if there was a clearance problem, the city maintaining that signal would not install another just like it after the first got whacked by a truck or some other high-clearance vehicle?

[Brandon]

Always attacking California...

Only after you decided to attack the rest of the US and claim that California is somehow exceptional.  Knock it off.
CalTrans has pluses and minuses, same as any other DOT.

[DaBigE]

That left turn signal still doesn't look like it has enough clearance...maybe 12-ft?  Does the extra ~4-ft really make that much of a difference in visibility?

Not wanting to sound like a smart-ass but don't you think if there was a clearance problem, the city maintaining that signal would not install another just like it after the first got whacked by a truck or some other high-clearance vehicle?

That thought crossed my mind as well.  However, I know of a few municipalities that have signs and signals routinely knocked out and they keep replacing them in the same spot.  Just drove past one of those spots on the way in this morning...knocked down yet again.

[jwolfer]

How about New Jersey... The state of NO LEFT TURNS... and therefore U turns... sometimes you see someone from out from out of state trying a U-Turn on a road with jughandles. 

[kphoger]

How about New Jersey... The state of NO LEFT TURNS... and therefore U turns... sometimes you see someone from out from out of state trying a U-Turn on a road with jughandles. 

You heard it here first!  No left turns in New Jersey! 

[Alps]

How about New Jersey... The state of NO LEFT TURNS... and therefore U turns... sometimes you see someone from out from out of state trying a U-Turn on a road with jughandles. 

You heard it here first!  No left turns in New Jersey! 

That would seriously complicate my commute

[swbrotha100]

The Tucson area has pretty consistent signage when it comes to intersections with dual left turn lanes. Probably better than anywhere else in Arizona.

[swbrotha100]

Speaking of dual left turns, are there a lot of places where there are permissive-protected dual left turns allowed? These signals are everywhere in the Tucson city limits. I supposed it works because the majority of signals in Tucson are lagging left. Most places outside the city limits would have permissive-protected dual left turns as an exception rather than the standard.

[Mr_Northside]

Speaking of dual left turns, are there a lot of places where there are permissive-protected dual left turns allowed?

I can't think of any dual LT lanes in PA that aren't protected only.  Of course that doesn't mean that some might not be found, but I'd bet it's rare.

[Ian]

Speaking of dual left turns, are there a lot of places where there are permissive-protected dual left turns allowed?

I can't think of any dual LT lanes in PA that aren't protected only.  Of course that doesn't mean that some might not be found, but I'd bet it's rare.

There is one that I know of near the Auto Mall at the intersection of Bartram and Essington Avenues in Philadelphia. This is actually the only permissive-protected dual left turn intersection that I'm aware of anywhere.

[Alps]

Speaking of dual left turns, are there a lot of places where there are permissive-protected dual left turns allowed?

I can't think of any dual LT lanes in PA that aren't protected only.  Of course that doesn't mean that some might not be found, but I'd bet it's rare.

There is one that I know of near the Auto Mall at the intersection of Bartram and Essington Avenues in Philadelphia. This is actually the only permissive-protected dual left turn intersection that I'm aware of anywhere.

Anywhere in PA? I might buy that. But that's all I'll buy.

[kharvey10]

South Carolina has some on 278 near Hilton Head Island