Evaluation of Roadway High-Mast Tower Lighting

Gibbons, Ronald; Bhagavathula, Rajaram; Williams, Brian; Kassing, Andrew; Hamen, Johann; Elkins, Daniel

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https://hdl.handle.net/2142/120920 Copy

Description

Title

Evaluation of Roadway High-Mast Tower Lighting

Author(s)

• Gibbons, Ronald
• Bhagavathula, Rajaram
• Williams, Brian
• Kassing, Andrew
• Hamen, Johann
• Elkins, Daniel

Issue Date

2023-10

Keyword(s)

• High Mast Lighting
• Street Lighting
• Lighting Equipment
• Lighting Systems
• Transportation Safety
• Visibility
• Human Factors
• Diamond Interchanges
• Traffic Speed

Abstract

This study conducted an evaluation of high-mast roadway lighting, which included a review of Illinois Department of Transportation’s high-mast lighting specification and a field experiment. The lighting specification was reviewed for potential cost-saving measures. Recommended changes included the use of an external drive mechanism, a design-by-application mounting ring, and using the industry standard handhole design. The field experiment consisted of two human factors evaluations. In one evaluation, participants were driven along I-57 through five interchanges with various lighting designs and answered questionnaires about the lighting. Results showed that interchanges that were fully lit outperformed partially lit interchanges for perceptions of comfort, safety, and visibility regardless of whether the interchange used conventional lighting or high-mast lighting. When comparing participants’ responses between high-mast lighting at full intensity or at a 50% dim level, there was no change in perceptions of comfort, safety, or visibility. In the second evaluation, radar sensors were placed at key locations at each interchange and the speed behavior of traffic was recorded and analyzed. Speed analysis showed that lighting designs using only high-mast lighting had a potential ±safety benefit via reductions in vehicle speed variation. Comparing high-mast lighting at full intensity and at a 50% dim level, the dimmed lighting resulted in a significant reduction in speed for exiting traffic. Furthermore, dimming improved safe speed behavior on ramp segments while not significantly affecting the speed behavior for vehicles traveling through the interchange. Recommendations based on the results include using full interchange lighting designs, using a single light type (conventional or high mast, but not both), using a lower light level, and dimming lighting during times of low traffic volume.

Publisher

Illinois Center for Transportation/Illinois Department of Transportation

Has Part

• https://doi.org/10.36501/0197-9191/23-021
• ISSN: 0197-9191

Series/Report Name or Number

FHWA-ICT-23-015

Type of Resource

text

Language

en

Sponsor(s)/Grant Number(s)

IDOT-R27-206

Copyright and License Information

No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161.

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