The Pennsylvania Department of Transportation and other state transportation agencies are required to provide edge line delineation on two-lane arterials when traffic volumes exceed 6,000 vehicles per day and the pavement width is at least 20 feet. Other combinations of pavement width and traffic volume may also warrant edge line delineation. The standard edge line width is 4 inches; however, an edge line width of 8 inches can provide greater emphasis for motorists. There is a need to evaluate the effectiveness of providing wider edge lines on horizontal curves to determine if they provide improved delineation for motorists on two-lane highways. The objective of this project was to evaluate the operational effects of using wider edge lines on horizontal curves along two-lane rural highways. A before-after observational study with comparison sites was used to evaluate the change in several performance measures, including mean speed, speed variance, encroachment frequency, mean lateral vehicle position in the travel lane, lateral vehicle position variance, and speed and lateral vehicle position differential between the tangent and midpoint of a horizontal curve. Day and night time periods were considered as were approach tangent and horizontal curve locations. The effects of vehicles traveling in the opposing travel lane were also considered in the evaluation. The results indicate that wide edge lines, applied to horizontal curves on two-lane rural highways in Pennsylvania, do not consistently change the encroachment proportion along curves, nor do they consistently change driver behavior patterns at all treatment locations as measured by speed and lateral vehicle position. The location of speed deceleration, based on a subjective assessment of speed profile plots, provides evidence that drivers recognize curves at night from a greater distance with wide edge lines when compared to similar curves with standard, 4-inch-wide lines.
Operational Effects of Wide Edge Lines Applied to Horizontal Curves on Two-Land Rural Highways
2006
102 pages
Report
No indication
English
Transportation & Traffic Planning , Transportation , Transportation Safety , Road Transportation , Highway Engineering , Road curves , Two lane roads , Rural highways , Horizontal curves , Speed patterns , Lane width , Road width , Highway design speed , Pennsylvania , State transportation agencies , Driver behavior , Traffic volume , Pavements , Performance measures , Motorists , Highway engineering , Delineation , Encroachment
Speed-Based Safety Evaluation of Horizontal Curves in Rural Highways
Springer Verlag | 2022
|Reliability-Based Design of Horizontal Curves on Two-Lane Rural Highways
Transportation Research Record | 2016
|Safety effects of wider edge lines on rural, two-lane highways
Elsevier | 2012
|Safety effects of wider edge lines on rural, two-lane highways
Online Contents | 2012
|Operating Speed Prediction Models for Horizontal Curves on Rural Four-Lane Highways
Transportation Research Record | 2008
|