Retroreflectivity General Information

Guidelines for Evaluating Public Interest Findings and Certifications
for Retroreflective Sheeting for Traffic Control Signs, Section 508 Captions

Figure 1. Graph. Overhead Sign Results for an SUV. This graph shows two families of curves. One family of curves shows how the legend luminance of different retroreflective sheeting materials changes as a SUV driver approaches a typical overhead guide sign. The second family of curves shows how much legend luminance is needed for the sign to be legible for various levels of accommodation (ranging from 50 percent to 95 percent). On the X-axis is the log of the luminance in candela per meters squared from 0.1 to 100, and on the Y-axis is the distance from the sign starting at 1000 ft and stopping at 200 ft. The graph also includes a legibility zone defined by a maximum legibility threshold of 640 ft and a last look limit of 200 ft. Within the legibility zone, the two families of curves show how the performance of retroreflective sheeting materials differs.

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Figure 2. Graph. Overhead Sign Results for a Heavy Vehicle. This graph shows two families of curves. One family of curves shows how the legend luminance of different retroreflective sheeting materials changes as a heavy vehicle driver approaches a typical overhead guide sign. The second family of curves shows how much legend luminance is needed for the sign to be legible for various levels of accommodation (ranging from 50 percent to 95 percent). On the X-axis is the log of the luminance in candela per meters squared from 0.1 to 100, and on the Y-axis is the distance from the sign starting at 1000 ft and stopping at 200 ft. The graph also includes a legibility zone defined by a maximum legibility threshold of 640 ft and a last look limit of 200 ft. Within the legibility zone, the two families of curves show how the performance of retroreflective sheeting materials differs.

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Program Contact

Cathy Satterfield

What’s New

Proposed Revision of the 2009 MUTCD – Compliance Dates NEW!

FHWA Technical Advisory T 5040.40: Center Line Rumble Strips NEW!

FHWA Memo: Technical Advisories for Rumble Strips NEW!

Roadway Departure Safety Implementation Plans

Roadway Departure Countermeasures

Roadside Design: Steel Strong Post W-beam. A guidance memo was issued on May 17, 2010 on the height of guardrail for new installations. Guidance regarding existing guardrail will be developed in the next several months, in consultation with AASHTO's Technical Committee on Roadside Safety.

Pavement Marking Retroreflectivity Notice of Proposed Rulemaking [HTML, PDF]

MUTCD Text of the Proposed Pavement Marking Retroreflectivity Standard

Summary of the MUTCD Pavement Marking Retroreflectivity Standard

Revised Assessment of Economic Impacts of Pavement Marking Retroreflectivity

Publications

Low Cost Treatments for Horizontal Curve Safety

The Safety Edge