The National Academies

NCHRP 20-07/Task 374 [Final]

Guidelines for Selecting Sign Sheeting Materials for AASHTO M268
[ NCHRP 20-07 (Research for AASHTO Standing Committee on Highways) ]

  Project Data
Funds: $75,000
Research Agency: Texas A&M Transportation Institute
Principal Investigator: Gene Hawkins
Effective Date: 10/1/2017
Completion Date: 3/31/2022

There are two standard specifications for sign sheeting materials in the United States: AASHTO M268 and ASTM D4956. The AASHTO specification is based more on nighttime driver needs and the ASTM specification is based mostly on the performance of different products. While both specifications classify sign sheeting materials, neither specification provides guidance to help agencies select the appropriate sign sheeting materials. ASTM D4956 is more of a product based specification while AASHTO M268 is more of a performance based specification. The AASHTO M268 specification was developed by a team of state DOTs so that sign sheeting materials can be classified in a meaningful way. Research is needed to develop guidelines for M268 for selecting the most appropriate sign sheeting materials.
The objective of this project is to develop guidance that can be used by highway agencies in the process for selecting sign sheeting materials using AASHTO M268. This guidance addresses current regulations, driver needs, the latest human factors research, cost, availability, durability, ease of use, maintenance, sign type, typical placement and other relevant factors. The research includes a critical review of previous research related to sign sheeting materials and their effectiveness, identify and evaluate the process currently used for selecting sign sheeting materials, and develop guidelines. The guidance describes the types of sign sheeting materials, the specific design conditions where they perform best, and develops scenarios for sheeting type use for specific sign locations according to driver needs. The guidance recommends sign sheeting types for sign design, location, and placement while taking into account the retroreflectivity of various sign sheeting types and economics.
The final project report can be found at link. In addition, a companion summary PowerPoint presentation file can be find here.


To create a link to this page, use this URL: http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3920