Details:

Creators:
Obeidat, Mohammed ; Rys, Malgorzata ; Russell, Eugene R.
Obeidat, Mohammed ; Rys, Malgorzata ; Russell, Eugene R. Less -
Corporate Creators:
Kansas State University. Transportation Center
Subject/TRT Terms:
[+]
Costs Energy Conservation Field Tests Laboratory Tests Lighting Overhead Traffic Signs Recommendations Retroreflectivity State Departments Of Transportation Surveys Visibility
Publication/ Report Number:
K-TRAN: KSU-11-6
Resource Type:
Tech Report
Geographical Coverage:
Kansas
Corporate Publisher:
Kansas. Dept. of Transportation
Abstract:
Roadway guide sign visibility during darkness is fundamental to driver safety, especially elderly drivers. Guide

sign visibility can be improved by external sign illumination or the use of retroreflective sheeting on signs. Because

energy conservation is essential in the midst of a worldwide energy crisis, various Departments of Transportation have

investigated usage of energy-efficient lighting technology with overhead guide signs.

This report presents results of a survey related to overhead sign lighting usability by states, a laboratory

experiment to compare the light distribution of five light sources used to illuminate overhead guide sign by several

states, a cost analysis for the tested light sources, a field experiment to compare the visibility of three retroreflective

sheeting used by states, a cost analysis for the tested retroreflective guide signs, and an analysis by determining the

most cost-effective method of increasing overhead guide sign visibility to drivers during nighttime.

A laboratory experiment was conducted to compare the light distribution of three conventional light sources:

Metal Halide, Mercury Vapor, and High Pressure Sodium, and two new generation light sources: Induction lighting,

and Light Emitting Diode. Combining two decision criteria, the light distribution and the cost, resulted in finding the

Induction lighting to be the recommended light source for those states that want to continue illuminating their

overhead guide signs. A field experiment was conducted to compare three types of sign sheeting, Engineering Grade

(type I), Diamond Grade (type XI), and High Intensity (type IV), in order to determine the sign sheeting material that

best improves sign visibility. Combining the decision criteria to compare these three retroreflective sheeting, the

visibility and the cost, High Intensity (type IV) is the recommended sign to be used by DOTs, followed by Diamond

Grade (type XI).

In comparing the best options used to increase sign’s visibility, sign illumination and sign retroreflectivity, it is

found that using retroreflective sheeting is more cost effective than sign illuminating.


Format:
PDF
Funding:
C1889
Collection(s):
US Transportation Collection University Transportation Centers
Main Document Checksum:
[+]
urn:sha256:1a77d369283d04d9d65ef6142d618be35fc5442280e039ba1b9c1d5d5e61c4b0
Download URL:
https://rosap.ntl.bts.gov/view/dot/28555/dot_28555_DS1.pdf
File Type:

Supporting Files

• No Additional Files

More +