how would one sign this situation better?
here, at the intersection of Kearny Villa Road and Miramar Road in San Diego, two lanes expand into four, as can be seen on this aerial view:
http://goo.gl/maps/YYM7H
now, the one lane assignment sign, which is almost right at the junction. it shows the lane configuration correctly.
http://goo.gl/maps/Hy0t5
however, there is no advance sign which shows how the two lanes become four. furthermore, when there is heavy traffic, one can see the four-lane assignment sign from a distance, but not the striping on the ground.
I can't imagine I'm the only one who has made the mistake of assuming that, because left-turning traffic is sufficiently high that 3 out of 4 lanes are assigned to turn left, that both of the original two lanes would become left turning lanes (the right one having a straight option)? Is there a standard sign which could be placed several hundred feet in advance that shows how the lanes open up?
another example is here:
http://goo.gl/maps/FBPio
the four-lane assignment can be seen when there are only two lanes. (don't look at the overhead view - it shows only three lanes; must be older.)
I fail to see the problem here. It's standard that if you want to turn left, be in the left lane. If you want to turn right, remain in the right lane. If you want to go straight, stay in either lane.
Now, if something is different, that's when a sign is posted. If the left lane were to become a left-only lane (as you suggest), then post a sign.
If someone is approaching the intersection for the first time, one would probably be unaware of how heavy traffic is, and why 3 left turn lanes are needed. One would just assume to be in the left lane approaching the intersection, then would notice that 3 lanes are available to turn left. And if one is aware of how busy traffic is at the intersection, they would just as likely already be in the left lane as well.
Thus, I see no reason to install further signage. It's fine as is.
I do not remember the exact situation, but there was something about the traffic pattern, or the way the road curved, that seemed to imply that both lanes turned into left-turning lanes.
Solution: post the sign referenced below farther upstream, preferably overhead.
Quote from: agentsteel53 on April 16, 2013, 01:09:29 PM
now, the one lane assignment sign, which is almost right at the junction. it shows the lane configuration correctly.
http://goo.gl/maps/Hy0t5
Quote from: kphoger on April 16, 2013, 02:51:57 PM
Solution: post the sign referenced below farther upstream, preferably overhead.
Quote from: agentsteel53 on April 16, 2013, 01:09:29 PM
now, the one lane assignment sign, which is almost right at the junction. it shows the lane configuration correctly.
http://goo.gl/maps/Hy0t5
the problem is, there are only two lanes farther upstream. it is not intuitive how two lanes become four.
Pavement arrows upstream as well, then. Straight and left for the left lane, straight and right for the right lane.
As jeffandnicole say, I'm not sure why anything would be necessary, since where the road is two lanes, it's just a common sense (to me) straight/left and straight/right. But since you drive that road, and I do not, I'll happily defer to your experience. And I don't think there's any reason why you couldn't post a sign on the two-lane portion that matched the lane assignments for those two lanes.
Quote from: Kacie Jane on April 16, 2013, 03:39:49 PMa sign on the two-lane portion that matched the lane assignments for those two lanes.
indeed. this is a different sign than the four-lane version.