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U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE.
Washington, D.C. 20590
May 10, 2019
In Reply Refer To: HOTO-1
Steven E. Walker, P.E.
State Design Engineer
Alabama Department of Transportation
1409 Coliseum Boulevard
Dear Mr. Walker:
Thank you for your letter of February 22, 2019, requesting an interpretation of the provisions of the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) regarding the design of Exit Direction signs for multi-lane exits with an option lane. Specifically, your request asks whether two Exit Direction sign designs developed by the Alabama Department of Transportation (ALDOT), which deviate from the designs described and illustrated in the MUTCD, otherwise comply with the provisions of the MUTCD.
The first ALDOT sign, shown in Figure 1 of your letter, is an overhead installation located in advance of the exit at the point where the option lane begins to widen. The sign has two diagonal upward pointing arrows at the bottom of the legend, presumably one centered above the option lane and the other centered over the lane that is being dropped at the exit. In this design the arrow on the right side is displayed within an EXIT ONLY panel with a black legend on a yellow background. The arrow on the left side designating the option lane is white and is within the green background of the sign. The stated intended use would be to replace the standard Exit Direction sign in the MUTCD that is shown located at the theoretical gore for two-lane interchanges designated as Intermediate or Minor, as defined in the MUTCD, with an option and dropped lane.
The second sign design, shown in Figure 2 of your letter, is stated to be used at intermediate or minor interchanges where Overhead Arrow-Per-Lane signing is present. This sign is intended to be used instead of the last Arrow-Per-Lane sign in the standard sequence of Arrow-Per-Lane signs, illustrated in Figure 2E-4, that is located just in advance of an exit. In contrast with the standard Arrow-Per-Lane sign that has an arrow representing each lane on the roadway, this sign would use a split arrow to represent all the through lanes as well as the optional exit lane, i.e. other through lanes would not be represented by individual arrows as normally displayed on Arrow-Per-Lane signs.
It is our official interpretation that neither of these two sign designs complies with the provisions of the MUTCD. Regarding the Exit Direction sign shown in Figure 1 of your letter, Section 2E.36 of the MUTCD states that where a through lane is being terminated (dropped) at the exit, the Exit Direction sign shall be placed overhead at the theoretical gore. At this point, the lanes illustrated by the arrows on the Exit Direction sign are both exiting lanes and therefore shall be identified accordingly on the sign with the words EXIT ONLY between the two diagonally upward-pointing arrows in a yellow background as illustrated in Figure 2E-11 of the MUTCD. It is important to note that the use of Lane Control (R3-8) signs appropriately sized for freeway application and located between the Advance guides signs, as well as an appropriately located Exit Direction sign at the theoretical gore, will help alleviate any potential misunderstanding of the lane configuration of the highway and exit at the point of exit. In addition, evaluations of this concept have consistently indicated that sign designs similar to what is proposed have not improved understanding that the option lane also allows for traffic to remain on the through route and therefore such leads to unnecessary lane changing by motorist intending to remain on the through route.
Regarding the proposed revision to the standardized Arrow-Per-Lane sign shown in Figure 2 of your letter, Section 2E.21 of the MUTCD states that an Arrow-Per-Lane sign shall include an upward-pointing arrow for each lane of the approach to the split or exit, and the shaft of each arrow shall be located approximately over the center of the lane to which it applies. The proposed design includes only one bifurcated arrow to illustrate both the optional exit lane as well as all the through lanes. This violates this requirement for an arrow for each lane present on the roadway.
We hope this information helps in your understanding of the requirement in the MUTCD regarding Exit Direction signs for option lanes on freeways and expressways. For recordkeeping purposes, this interpretation has been assigned the following Official Ruling number and title: "2(09)-151 (I) – Exit Direction Signs for Multi-Lane Exits with Option Lane". Please direct any inquiries regarding this information to Mr. Marty Calawa, email@example.com, (202) 579-2549.
Mark R. Kehrli
Director, Office of Transportation
United States Department of Transportation - Federal Highway Administration