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Title:

Examining the Nighttime Legibility of Internally Illuminated Traffic Signs with Specific Distance-Luminance Profiles

Accession Number:

01126665

Record Type:

Component

Availability:

Transportation Research Board Business Office

500 Fifth Street, NW
Washington, DC 20001 United States

Abstract:

Traffic signs communicate roadway regulations, warnings, and directions. These signs must perform adequately under both daytime and nighttime conditions. Retroreflective sheeting materials are used so that traffic signs can be seen and read at night. There are many types of retroreflective sheeting materials available commercially. However, there is a lack of guidance in terms of which retroreflective sheeting materials to use where. Many agencies conduct their own evaluations as a result. However, when evaluating traffic signs with the current array of materials, the distance-luminance profiles are limited to those provided by the materials currently available. In an effort to expand the possibilities of evaluating nighttime traffic signs, the research team built internally illuminated traffic signs equipped with wireless variable luminance controls that were synchronized with a test vehicle so that the luminance of the sign changed as a function of the distance of the test vehicle to the sign. Various luminance profiles were tested as a proof of concept and in examine what might be considered a desired or even ideal distance-luminance profile. Overall, the results show that increasing sign luminance will lead to increased legibility distances but there appears to be a point of diminishing returns. The results demonstrate that it is not only the amount of luminance available to a nighttime driver, but just as important is how the luminance is distributed along the critical approach to the sign (where the information on the sign is attainable in terms of driver visual capabilities).

Monograph Accession #:

01120148

Report/Paper Numbers:

09-3004

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Young, Sarah
Carlson, Paul J
Park, Eun Sug
Miles, Jeffrey David

Pagination:

21p

Publication Date:

2009

Conference:

Transportation Research Board 88th Annual Meeting

Location: Washington DC, United States
Date: 2009-1-11 to 2009-1-15
Sponsors: Transportation Research Board

Media Type:

DVD

Features:

Figures; Photos; References (8) ; Tables (5)

Subject Areas:

Highways; Materials; I35: Miscellaneous Materials

Source Data:

Transportation Research Board Annual Meeting 2009 Paper #09-3004

Files:

TRIS, TRB

Created Date:

Jan 30 2009 7:23PM