One of the interesting and important things that was presented at the 2003 ITE meeting in Seattle is the fact that flashing yellow arrow permitted left turn phasing WILL be included in the next edition of the MUTCD. The folks in charge were just wrestling with the specific language. The hardware is an all arrow four section head with a green, two yellows and a red lens. The operational sequence of the Protected/Permitted phasing is Steady Green Arrow (protected), Steady Yellow Arrow (Change), Flashing Yellow Arrow (permitted), Steady Yellow Arrow (Change) and Steady Red Arrow (stop). This configuration can be operated as Protected/Permitted, Permitted/Protected, Protected Only or Permitted Only.

In the interim, according to Scott Wainwright of FHWA, anyone who wishes to "experiment" with this can do so by applying to the FHWA and providing a three year history of before and after collision data. A sample form can be found at http://projects.kittelson.com/pplt/, under the hot link called "DOCUMENTS", which leads to "TECHNICAL DOCUMENTS", which ends at "FHWA Request for Experimentation". You can fill out the form right on the screen, print it and send it in. How much more convenient can this be? Approval of your application is assured. This web site also provides an animated display of the operation of these signals as well as all of the working papers and the final report. The final report, NCHRP Report 493, is also available through TRB.

The next edition of the MUTCD will also permit the use of flashing red permitted left turn phasing under "certain" circumstances where it has been determined that a complete stop before proceeding is required. In my opinion, this would legitimize the flashing red arrow P/P left turns in Delaware and Cupertino and the flashing red P/P left turns in Michigan. The influence of Raymond Pusey (Delaware) cannot be underestimated.

Before you consider installing "doghouse" circular green permitted left turn signals, I urge you to consider that the City of Seattle has been successfully using flashing yellow for permitted left turns for forty (40) years. We had one bad experience with "doghouse" P/P signals at Pruneridge Avenue and the HP Driveway and the City of Modesto had a disaster at one of their intersections. Details on request. The State of Delaware had been using flashing red arrow permitted left turns for many years before we installed them in Cupertino. That means decades before today. The cities of Fullerton and Pomona are installing flashing yellow P/P left turn signals under experimentation by the method above and permission of the CTCDC. Further, the State of Oregon (ODOT) is installing FYA as are many cities in Oregon. My recommendation is and always has been flashing yellow arrow permitted left turn signals.