Left-turn Restrictions

NCHRP Report 279 Intersection Channelization Design Guide is a good general reference. It is available in photocopy from the Transportation Research Board for about $10.00.

I'm not getting from your description exactly what you are trying to accomplish. Are you trying to restrict left turns on the intersection approaches or within the intersection? The latter generally requires something other than a conventional intersection design.

Thanks. I'll look into that reference.

There is a existing minor residential street (currently a dead-end) that will connect to a new minor arterial. We are being required to prevent vehicles from the residential street from turning left onto the new arterial.

Adam
Rupert Engineering, Inc
Auburn, WA

Are you making provisions for alternate access? An indirect left of some sort?

What about emergency vehicles, school busses and deliveries?

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

Oregon DOT has a discussion paper for Right-In/Right-Out channelization


on their website that provides a lot of information including references that would be applicable to a Right-Out configuration.

Dont forget some vehicles may make the left turn by turning right and then U turning. Their willingness to do this is determined by the alternative route they have to follow instead. A longer alternative makes a higher probability they will do this. Careful planning of the length of the blocking island and all the possibilities is required.