Nov 01, 2007

A proposed new standard will provide a practice for inspecting and evaluating the retroreflective properties of longitudinal non-intersection pavement markings. The proposed standard, WK16773, Practice for Evaluating Retroreflectance of Pavement Markings Using Portable Hand-Operated Instruments, is being developed by Subcommittee D04.38 on Highway Traffic Control Materials, which is part of ASTM International Committee D04 on Road and Paving Materials.
 
According to Paul Carlson, Texas Transportation Institute, Texas A&M University System, the proposed standard will replace D 6359, Specification for Minimum Retroreflectance of Newly Applied Pavement Marking Using Portable Hand-Operated Instruments, which was withdrawn in 2006.
 
“D 6359 was a great starting place and provided a common method for sampling pavement marking retroreflectivity to assess the quality versus a standard,” says Carlson, who is chair of Task Group D04.38.07 on Pavement Marking Retroreflectivity. “However, as the standard aged, three main issues were noted.” These issues were:

• As users became familiar with D 6359, they began to modify their own practices because the time and resource requirements needed to fulfill the sampling protocol described in D 6359 were viewed as excessive.
• D 6359 contained one pair of minimum retroreflectivity levels (for yellow and white markings) that were to be used as the standard that all newly applied markings were to satisfy. Innovation over the last decade has led to a large range of pavement marking systems, which has led to a large range of pavement marking retroreflective levels, making the original pair of retroreflectivity levels in the standard not applicable to all systems.
• D 6359 only applied to new markings. Changes throughout the world are placing more emphasis on maintaining the retroreflectivity of pavement markings. This created a need to develop a specification that pertained to the inspection of pavement marking retroreflectivity over time and not exclusively to newly applied pavement markings.
 
The proposed new standard, which will be used by owners and installers of pavement markings, addresses these issues. WK16773 can be applied to both new and in-service markings and there is no retroreflectivity set in the proposed standard. Instead, the user is required to set the standard retroreflectivity level per their own expectations and desires. “In addition, there is a three-step process for inspecting and evaluating pavement markings,” says Carlson. “Each step of the proposed practice provides more statistical confidence in the determination of the measured pavement marking retroreflectivity level.”

Participation in the continuing development of WK16773, particularly in the area of user expertise, is welcome.

For further technical information, contact Paul Carlson, Texas Transportation Institute, Texas A&M University System, College Station, Texas (phone: 979/845-6004; Paul-Carlson@tamu.edu). Committee D04 meets Dec. 4-6 at the December committee week in Tampa, Fla. For membership or meeting information, contact Daniel Smith, Technical Committee Operations, ASTM International (phone: 610/832-9727; dsmith@astm.org).

Release #7817