Safety Evaluation of Profiled Thermoplastic Pavement Markings

Appendix B. Additional Installation Details from South Carolina

This appendix presents additional details provided by SCDOT regarding its installations of profiled thermoplastic pavement markings.

1. Can you provide average installation costs per line-mile and the estimated service life of the products used?

   An average cost would be $0.50/linear ft. Service life of 5 years.

2. Are raised or inverted profile patterns applied?

   Primarily, raised profiles are used, and the thermoplastic is preferred to the disc but both are allowed.

3. On which of edge lines, center lines, and lane lines are profiled thermoplastic markings applied?

   Typically, the edge line only is treated.

4. Can you provide any installation guidelines for the markings (e.g., width, spacing, pavement types on which the markings are not suitable)?

   Criteria for rumble strips including profiled thermoplastic markings [are] available at: http://info.scdot.org/Construction_D/Engineering%20Directive%20Memorandums/EDM53.pdf.
   
   Specifications [are] available at: http://www.scdot.org/doing/technicalpdfs/supspecs/profile_marking_system.pdf.

5. Are there any criteria for deciding which roads receive the profiled thermoplastic markings (e.g., a certain level of AADT or critical crash rate)?

Rumble strips shall be placed on shoulders or edge lines of all partial and non-controlled access roadways, subject to the following criteria:



1. Roadway is classified as rural.
2. ADT [average daily traffic] is 500 vehicles per day or greater.
3. Posted speed limit is 45 mi/h or greater.
4. Existing roadway width is 20 ft or greater.
   
   

Thermoplastic profiled markings are an acceptable alternative only if rumble stripes are not feasible due to structural insufficiencies of a paved shoulder where milled in rumble strips may damage the surface/shoulders.

6. Were any other safety countermeasures installed at the treatment sites evaluated by this study in conjunction with the profiled thermoplastic markings?

   A select few projects may have been through resurfacing efforts but is minimal.

7. Please describe any notable challenges related to the installation of the markings and how you overcame them.

   Not aware of any challenges.

8. Please describe any notable challenges related to the maintenance of the markings and how you overcame them.

   Their use is limited due to the short lifecycle and comparable cost to milled in rumble strips. We are not necessarily a snow State, but any snow removal or shoulder leveling would practically remove the markings.

9. What lessons learned or recommendations would you share with another agency interested in the widespread application of profiled thermoplastic markings?

   Obviously, use of the profile should be in a State with limited snow activity. One should also consider that when shoulders are leveled that the profiled marking will likely be removed. Where possible, milled-in rumble strips should be the preferred method based on cost and longevity.