Details:

Creators:
Jackson, N. Mike ; Carlson, Paul J. ; Ye, Fan ; Jackson, Georgia R.
Jackson, N. Mike ; Carlson, Paul J. ; Ye, Fan ; Jackson, Georgia R. Less -
Corporate Creators:
University of North Florida
Subject/TRT Terms:
[+]
Alternatives Analysis Brightness Highway Safety Life Cycle Costing Lighting Luminance Overhead Traffic Signs Reflective Signs Retroreflectivity Sign Sheeting Visibility
Publication/ Report Number:
BDK82 977-07
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION;NTL-SAFETY AND SECURITY-Highway Safety;
Abstract:
Effective highway signing is an important component of driver decision making, comfort, and

safety. Like many agencies across the country, overhead sign lighting has been used by the Florida

Department of Transportation (FDOT) to improve visibility. However, the availability of newer and more

efficient retroreflective materials has created a new challenge for state transportation agencies going

through sign upgrade programs and considering the need for sign lighting. FDOT initiated this study to

investigate whether high intensity reflective sheeting can be used to replace overhead sign lighting.

Field data was collected to assess the conditions of Florida signs in terms of the MUTCD

minimum maintained retroreflectivity levels. In addition, a luminance computation model was developed

to calculate sign legend luminance under various situations, including different sign lighting technologies,

different geometrics and sign locations, and different amounts of sign dirt and sign aging. By comparing

the calculated luminance of a specific sign at a specific situation with the legibility luminance levels

required by older drivers, sign lighting needs were assessed.

A life-cycle cost spreadsheet was developed and used to calculate the cost of replacing the current

sign sheeting in Florida with high reflective sheeting and the cost of installing/upgrading sign lighting.

Based on this analysis, we found that under the conditions considered (either on straight and flat

roadways or horizontal curves, in rural areas or urban areas), the most cost effective approach to maintain

overhead guide luminance is to use (installing or replacing with) induction or LED luminaires. The results

also indicate that a viable alternative (in terms of maintaining luminance and being cost effective) would

be to use either Type VIII or Type XI legend sheeting materials and forgo sign lighting. For Type XI

sheeting materials, sign lighting would be needed along horizontal curves in rural areas with radii of 880

ft and horizontal curves in urban areas with radii of 2500 ft or less.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:cabbf3f5c47f24bd4ad9cd312516ad3230dbd8969e6ae6ccc813e4c830b9d65b
Download URL:
https://rosap.ntl.bts.gov/view/dot/25979/dot_25979_DS1.pdf
File Type:

Supporting Files

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