Minnesota Department of Transportation
Office of Traffic Engineering
Mail Stop 725, 2M Floor
395 John Ireland Blvd.
St. Paul, MN 6616.6- 1889

December 10, 2001

Shelley J. Row, P.E.
Director, Office of Transportation Operations
FHWA (HOTO-1)
400 7th Street SW
Washington, DC.C720590

In Reply Refer to: Roundabout Warning Sign
Request to Experiment

Dear Ms. Row:

The Minnesota Department of Transportation requests to;experirnent with an advance warning sign design for roundabouts. In accordance with Section lA.10 of the 2000 MUTCD, I offer the following for your consideration:

1. The first roundabouts scheduled for construction next year in Minnesota are at two interstate ramp terminals. In reviewing Section 20.34,' we do not feel that the roundabout warning symbol sign (Sign W2-6) adequately indicates the direction of traffic movement on the roundabout, especially to unfamiliar motorists.

2. Mn/DOT proposes to use a modified sign design that includes an aixow head to wan) motorists approaching the roundabout. The December 28, 2000 Federal Register stated that three states had commented in favor of a different symbol (from the one proposed by the NCUTCD) that was similar to the roundabout symbol used in Europe. Howeyer, the register stated "...the FHWA believes it is important to take advantage of this Opportunity to include a sign in the MUTCD for circular intersections. Until further research can be, done on another symbol, the FHWA plans to include the symbol submitted by the NCUTCD...". We feel that our design will clearly indicate to motorists their direction of travel as they approach a roundabout.

3. Attached is a copy of our proposed sign design.

4. In the development of our modified sign design, we chose a design similar to the design depicted in the advance flyer of ROUNDABOUTS_ AN INFORMATIONAL GUIDE published by the US DOT FHWA (copy attached). Although this sign design has not been. used and since; this will he motorists' first exposure to roundabouts on state highways in Minnesota, we feel that our proposed advance warning' sign design more explicitly conveys how the upcoming roundabout affects their driving movement. Since motorists in Minnesota are used to turning left orright at intersections, our proposed design will indicate in advance of the intersection which direction they are required to turn to negotiate the roundabout.

5. This proposed sign design is not protected by a patent or copyright.

6. The proposed locations for this sign are on the exit ramps on 1-35 at Exit 48 north of Owatonna, Minnesota. This is a diamond interchange, which will have both ramp terminals reconstructed to a roundabout design. Mn/DOT intends to fabricate and install these advance warning signs with state forces.

7. Mn/DOT forces will monitor these roundabouts once they are constructed and permanent signing has been installed. Thetime period for experimentation will be for two years from the date of field installation of the proposed advance warning signs. During this time, we will have our maintenance forces periodically check the signs to make sure they are properly maintained. In addition, Mn/DOT will log any phone calls received regarding these two sign installations. Since Mn/DOT has a maintenance office within 5 miles of this interchange, our state forces can respond immediately to any problems arising regarding these signs. No before studies will lie done since we are proposing to install this modified advance warning sign when the roundabouts initiğlly open to traffic_ if we determine that this advance warning sign is ineffective in any way (through_ contact with state patrol or responses from motorists), we will either replace or supplement this sign with appropriate signing to ensure motorists' safety. If these signs prove to be effective during the evaluation period and do not create any safety l,a7ards, we will request that the 2000 MUTC.D and MnMUTCD be changed to include this warning sign as an optional method to provide road users with advance warning of a roundabout intersection.

8. Mn/DOT will comply with the terms specified in Section IA_10, 3" Guidance, Item H (Page IA-9).

9. Mn/DOT will provide a report semiannually, and a final report at the end of the two year experimentation period to Dave Kopacz, FHWA Division Office in St. Paul, Minnesota, who will forward this report on to the FHWA s-Office of Transportation Operations. This report will include a summary of any phone calls and comments received by Mn/DOT, as well as any maintenance activities required on, these signs.

If you have any questions about this experiment, please contact Terry Ward, Mn/DOT Rochester District Traffic Engineer, at 507-280-5035.

Sincerely,
Gary Thompson
State Traffic Engineer
cc: Michael Spielmann

Click here to view an image of the Advanced Warning Sign for Roundabouts. Scroll to the last page of the PDF to view the image.