This study involved an evaluation of large-scale installations of both hydrocarbon and alkyd extruded thermoplastics as lane delineation on sections of interstate highways having open-graded surfaces. The objective of the study was to evaluate the performance of thermoplastics as lane delineation and to compare the performance of hydrocarbon versus alkyd formulations.

Data were collected on a periodic basis over an 18-month period. Data collection consisted of daytime observations of the appearance and durability of the thermoplastic material along with reflectivity measurements using a portable retroreflectometer.

The evaluation revealed that both the hydrocarbon and alkyd extruded thermoplastic material maintained their appearance, durability, and reflectivity over the 18-month study period. It was found that the alkyd formulation maintained a higher level of reflectivity than the hydrocarbon formulations.

Based on performance, it was recommended that extruded thermoplastic continue to be used as a lane delineation material, and its use be expanded to other bituminous pavements on high volume roadways. Either formulation could be used, but it was recommended that the installations on the open-graded pavements continue to be monitored to determine if either formulation performs substantially better on a long-term basis.

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