Citation

Craus J, Livneh M. Transp. Res. Rec. 1978; 685: 7-13.

Copyright

(Copyright © 1978, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This paper deals with the various parameters required for design of a horizontal curve, namely the relation between superelevation rate and curve radius. These parameters are derived from the characteristics of a person-vehicle-environment system. The lateral acceleration that constitutes the physical output from this system determines the critical case, for which the radius is minimum. The data used here are taken from studies dealing with human factors and traffic characteristics. The maximum superelevation rate is determined by limiting the negative lateral acceleration for slow vehicles and by assuring safe driving for fast vehicles. The development of the relation between superelevation rate and curve radius for any constant design speed is based on driver expectation that the pressure exerted on the steering wheel will decrease with increasing curve radius. The findings are compared with the U.S. and German guidelines. The criteria developed here are concluded to be reasonable and the findings useful for design pruposes.