From: Martha Kapitanov
To: Safety Field
Date: 4/24/02 10:15:22 AM
Subject:Alternate Merge Signing--Responses

I want to thank everyone for so promptly getting back to me with your state information. In this e-mail, I have included information for the states that have used this sign and/or have initiated a study for future use.

Request:
In Virginia, we have had a request to install signs advising motorists to use the full length of a right (drop)lane and then alternately merge where two lanes merge into one. VDOT informed me that this has been used in Pennsylvania at some temporary construction work zone lane closures and it works well under such conditions when congested. However, this request is for a permanent location, not a work zone. Is your state using this setup in a permanent location and if so, what are there experiences?

Responses to my request:

David Morena --No, Michigan is not exploring this concept . I wish they would . Nebraska has reported using this concept - in work zones - and I believe this would go a long way to reduce the stress experienced by good drivers in a merge, who get passed up by impatient drivers in the closed lane.

Nebraska did not abandon the concept of early merge, however. Even though they had signs instructing motorists to occupy both lanes, the actual merge point (with a sign "Merge Here") was placed sufficiently in advance of the lane closure to keep flow smooth.

Nick Fortey--A few months ago, an Oregon DOT engineer visited Pennsylvania and saw the late merge concept in action. Mike Castellano of the Pennsylvania Division provided me a copy of the paper by Pesti, et. al. in Transportation Research Record 1657 which evaluated the late merge treatment and a copy of Penn DOT's June 11, 200 memo to their district offices advocating their use. I sent the materials to ODOT but, as of yet, they have not considered its use in any work zones, although I think it still holds promise in some applications. We have not used the late merge in any permanent applications.

Mike Castellano-PA does use it in work zone locations and it works well. The Univ. of Nebraska did a research paper a few years ago on it and had favorable findings for capacity reduction, etc. I do not believe PA uses it in permanent locations, at least I have not heard of it. VDOT could certainly try it out with temporary signing at those permanent locations and if it works, make the sign installations permanent.

Bonnie DuBose--CT has initiated a study to develop, field test and evaluate a new symbol warning sign (Alternate Merging) after signalized intersections. The intent of this sign will be to improve the traffic flow and merging pattern at the test sites. These test sites are experimental; there is an agreement to restore the site to a condition that complies with the provisions of the MUTCD. So for now, the request is for a temporary situation. Please see attached files.

Martha C. Kapitanov
FHWA-VA Division
Highway Safety Engineer
P.O. Box 10249
Richmond, VA 23240-0249
Phone (804) 775-3352
Fax (804) 775-3356