Ask the Expert

Technical questions about the project?  Ask Shawn, our Resident Expert, at Expert@Safe42.Org


Q:  How will the two-way left-turn lane (TWLTL) work with closely spaced entrances / exits and driveways?  Who will be accorded the right-of-way?

A:  Essentially the space in the TWLTL will be first come first serve...and most folks will have to perhaps relearn that and the way the TWLTL actually works.  From a driveway or side street, you actually pull into the TWLT, stop and wait for a gap in traffic before merging right into the travel lane.  Because of the closely spaced driveways and entrances, you probably won't be able to use the TWLTL as an acceleration lane.  It truly will become a lane to pull into and wait to either turn or blend in with traffic.  Passing traffic in a TWLTL is actually illegal and unsafe.  For turning into a business or driveway, you need to merge left into the TWLT near the driveway or business and wait for a gap in opposing traffic before turning left. 

When two or more vehicles are head-to-head, each one wanting to turn in opposite left directions, courtesy and sight distance may suggest that you let one vehicle make its turn before you make your turn. (This may happen at Mt. Holly Avenue and Jane Street.)

The FHWA offers some guidance on this in the document and illustration linked at the bottom of this page. 

Two-way left-turn lane driving (Source: Federal Highway Administration)

Shawn Dikes, AICP, has been a professional in the transportation field for almost 20 years and is the Chair of the Transportation Committee for the Crescent Hill Community Council, neighboring community to the project. 
Here are his thoughts in a recent letter linked at the bottom of this page:
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Anne McMahon,
Mar 5, 2012, 1:43 PM
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Anne McMahon,
Mar 5, 2012, 1:41 PM