Option lanes with a red arrow

[1995hoo]

I was just discussing the intersection of 18th Street and Constitution Avenue, NW, in Washington, DC, with someone and I found myself wondering how common this configuration is elsewhere.

I'll start with a Street View link. The picture is rather old and the road has been repaved, but all the pavement markings, signs, and traffic lights remain the same: http://goo.gl/maps/9hrzg

The Street View camera in this image is facing east along Constitution (see the Washington Monument in the background). Notice the left-turn configuration of a restricted lane and an optional turn lane, both subject to a red left-turn arrow while thru traffic has a green light. In the morning and evening rush hours the traffic is a hell of a lot worse than is seen in this picture and I can tell you that the rare driver who tries to make a left turn from the optional turn lane does so at great risk to himself in terms of (a) nobody expects him to stop, (b) they become enraged if anyone does stop there, and (c) he risks getting run into as he turns because the mandatory left-turn lane is routinely ignored by drivers who go straight out of a desire to use it to bypass the slow/stopped traffic in the other three lanes.

Anyway, the part of this intersection that seems stupid is the way the optional left-turn lane is configured such that someone turning left has to stop in that lane while people going straight still have a green light. That's what's making me wonder how common this configuration is elsewhere. Obviously, a driver wanting to go straight has no excuse if he rear-ends someone. He might have a reason for being angry if someone wanting to turn left isn't using a turn signal (it then looks like you're just an idiot for stopping at a green light), but that's still not a reason to fly into a rage honking and finger-flipping.

[jeffandnicole]

I'm quite sure that's not a proper setup, due to the obvious conflict.

[M3019C LPS20]

Those traffic signals are too close to each other.

I recall that M.U.T.C.D. states an adequate distance of the placement of individual vehicular heads. Can't remember the number off the top of my head, though.

[roadfro]

There is nothing OK about this setup. It should be split phased.

I seem to recall a similar situation somewhere else in DC...it's been too long since I visited so cannot remember now. I think it was near a bridge crossing.

[Big John]

Those traffic signals are too close to each other.

I recall that M.U.T.C.D. states an adequate distance of the placement of individual vehicular heads. Can't remember the number off the top of my head, though.

8 feet minimum apart for signals operating the same function.  But for different functions, such as a signal for through traffic and a signal for turning traffic, the signals can be placed adjacent to each other.

[Alps]

http://goo.gl/maps/3BPgh
Oh, Mass.

[M3019C LPS20]

Those traffic signals are too close to each other.

I recall that M.U.T.C.D. states an adequate distance of the placement of individual vehicular heads. Can't remember the number off the top of my head, though.

8 feet minimum apart for signals operating the same function.  But for different functions, such as a signal for through traffic and a signal for turning traffic, the signals can be placed adjacent to each other.

Yes, you're right. Now I remember.

In any case, that set-up there in D.C. should be reconfigured.

[kphoger]

I agree that the setup is rather weird, but it's only a small step away from the same deal without stoplights, which we've already discussed.  Considering there's a totally free through lane, and that traffic not turning left does get a green light, I can't really say it's totally bonkers.

[roadman]

http://goo.gl/maps/3BPgh
Oh, Mass.

Department of Conservation and Recreation (DCR), not MassDOT.  DCR considers compliance to the MUTCD as optional, despite a long standing state law to the contrary -

http://www.malegislature.gov/Laws/GeneralLaws/PartI/TitleXIV/Chapter85/Section2

[1995hoo]

I agree that the setup is rather weird, but it's only a small step away from the same deal without stoplights, which we've already discussed.  Considering there's a totally free through lane, and that traffic not turning left does get a green light, I can't really say it's totally bonkers.

What's screwy, though, is if someone stops in the option lane wanting to turn left when the straight-through traffic has a green light. Obviously in the Street View image that's no big deal because it's easy to go around, but traffic isn't usually quite that light through there.

[kphoger]

Right, that's the screwy part.  It's little different than someone stopping here for a stream of oncoming traffic.  The only difference is why the driver stopped (stoplight versus oncoming traffic); the effect on traffic is the same–at least temporarily.

[dfnva]

That setup is also present elsewhere in DC at Westbound Independence Ave SW to Southbound 12th St SW.

[Alps]

DCR considers compliance to the MUTCD

That's funny.

[cpzilliacus]

I was just discussing the intersection of 18th Street and Constitution Avenue, NW, in Washington, DC, with someone and I found myself wondering how common this configuration is elsewhere.

I'll start with a Street View link. The picture is rather old and the road has been repaved, but all the pavement markings, signs, and traffic lights remain the same: http://goo.gl/maps/9hrzg

Remember that this part of Constitution Avenue, N.W. is maintained by the National Park Service, and not DDOT (no trucks allowed between Virginia Avenue, N.W. and the entrance to I-66 and the T. Roosevelt Bridge (and no trucks allowed on the bridge either)).

[cpzilliacus]

That setup is also present elsewhere in DC at Westbound Independence Ave SW to Southbound 12th St SW.

There's a very similar right turn on Bladensburg Road, N.E. northbound approaching New York Avenue (also U.S. 50).  GSV here.