This paper examines procedures for setting curve advisory speeds, identifies issues associated with these procedures, and describes a proposed procedure that overcomes many of these issues. The proposed procedure consists of three elements: a criterion for setting the curve advisory speed, a method for determining this speed, and an engineering study method that confirms the need for an advisory speed plaque. One conclusion is that challenges associated with the use of the ball-bank indicator hinder achieving curve advisory speeds that are uniform in curves and consistent with driver expectation. The proposed procedure is shown to overcome these challenges.
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References
1.
Manual on Uniform Traffic Control Devices.FHWA, U.S. Department of Transportation, 2003.
2.
ChowdhuryM., WarrenD., BissellH., and TaoriS.Are the Criteria for Setting Advisory Speeds on Curves Still Relevant?ITE Journal, Washington, D.C., Feb. 1998, pp. 32–45.
3.
BonnesonJ. A., PrattM., MilesJ., and CarlsonP.Development of Guidelines for Establishing Effective Curve Advisory Speeds. Report FHWA/TX-07/0-5439-1. Texas Department of Transportation, Austin, Oct. 2007.
4.
ChowdhuryM. A., WarrenD. L., and BissellH.Analysis of Advisory Speed Setting Criteria.Public Roads, Vol. 55., No. 3, 1991.
5.
RitchieM. L.Choice of Speed in Driving Through Curves as a Function of Advisory Speed and Curve Signs.Human Factors, Vol. 14, No. 6, Dec. 1972.
6.
LylesR. W., and TaylorW. C.NCHRP Report 559: Communicating Changes in Horizontal Alignment.Transportation Research Board of the National Academies, Washington, D.C., 2006.
7.
A Policy on Geometric Design of Highways and Streets, 5th ed.AASHTO, Washington, D.C.,2004.
8.
Traffic Control Devices Handbook.Chapter 4. Institute of Transportation Engineers, Washington, D.C., 2001.
9.
CarlsonP., RoseE., ChryslerS., and BischoffA.Simplifying Delineator and Chevron Applications for Horizontal Curves. Report FHWA/TX-04/0-4052-1. Texas Transportation Institute, College Station, 2004.
10.
MoyerR. A., and BerryD. B.Marking Highway Curves with Safe Speed Indications.Highway Research Board Proceedings, Vol. 19, 1940, pp. 399–428.
11.
MerrittD. R.Safe Speeds on Curves: A Historical Perspective of the Ball Bank Indicator.ITE Journal, Sept. 1988, pp. 15–19.
12.
GlennonJ. C., and WeaverG. D.Highway Curve Design for Safe Vehicle Operations. In Highway Research Record 390.HRB, National Research Council, Washington, D.C., 1972, pp. 15–26.
13.
BonnesonJ. A.NCHRP Report 439: Superelevation Distribution Methods and Transition Designs.TRB, National Research Council, Washington, D.C., 2000.
