TWLTL at Intersection

[NateMH]

Hi, My son recently took his driving test and came upon a newly configured intersection that he was not familiar with. The NB-SB road (Chestnut) originally was a two-lane road, but was recently reconfigured to include bike lanes and a TWLTL on the south leg. The driving test requires him to travel NB on Chestnut and turn left onto Eight, which he had done many times before the intersection was reconfigured. Unfortunately, for the driving test, the newly reconfigured intersection with the TWLTL confused him, and he ended up making the left turn onto Eight from the NB thru lane. The proctor failed him immediately and said he made the left turn from the wrong lane.

I thought that was a little harsh. I also think the intersection design is a bit odd since there’s so many opportunities for head-on conflicts. For example, a NB left turn vehicle could come into conflict with a WB left turn vehicle that decides to use the TWLTL. There are no driveways along the SE corner of the intersection so why extend the TWLTL all the way to the intersection. Maybe they want better flow for NB traffic, but there’s not a lot of NB LT traffic so couldn’t they have just installed a dedicated NB LT lane?

Has anyone seen a design like this before?

 

[ACtrafficengr]

If your state is like most, the traffic law says you have to make a left turn from the leftmost lane unless otherwise allowed by an official traffic control device. In this case, that's the TWLTL.

From the yellow crosswalks, I'm guessing this may be in California. CA has it's own version of the Manual on Uniform Traffic Control Devices, and I'm familiar with the FHWA version.

Personally, I would have either squeezed in a southbound turn bay, or used a flush median on the far side of the intersection. I think that would have made it clearer that the right lane was for through/right traffic.

My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/