Citation

Dell'Acqua G, Russo F. Balt. J. Road Bridge Eng. 2010; 5(2): 89-97.

Copyright

(Copyright © 2010, Vilnius Gediminas Technical University, Publisher Technika)

DOI

unavailable

PMID

unavailable

Abstract

This article reports on a study of driver speed factors on two-lane rural (low volume) roads. The authors introduce the study with a discussion of roadway alignment consistency for travel safety, in context with current operating speeds. A design inconsistency can surprise drivers by violating their expectations, thus increasing the chance of delayed response times, speed errors, and unsafe driving maneuvers that may lead to higher collision risk. The present study was conducted on low-volume roads in Southern Italy without spiral transition curves between geometric tangent and circular elements on the horizontal alignment. The researchers used a standard methodology, widely employed in the literature, to evaluate the applicable deceleration and acceleration rates at each circular curve transition segment length. They used their results to develop four equations for speed prediction models on tangents and curves. The authors conclude that once real deceleration and acceleration transition length are known, a continuous operating speed profile can be designed for the total length of the roads.