Performance Evaluation of No Track Thermoplastic Traffic Markings

No track thermoplastic is a relatively new thermoplastic traffic marking material which can be installed on newly constructed asphalt pavement shortly after finishing paving operations. The main objectives of this study are (1) to develop a test procedure that can be used to determine whether a thermoplastic traffic marking is a no track thermoplastic traffic marking and (2) to run field tests to obtain performance data through real applications of industry-proclaimed no track thermoplastic traffic markings. Sixteen transverse lines were installed in the field for performance evaluation. The research team measured several parameters in the field such as appearance, retroreflectivity, and color. By comparing the testing parameters between no track and regular thermoplastic traffic markings, the research team intended to select a parameter that can be used to develop technical specifications to help decision makers define no track thermoplastic traffic markings. It was found that the best parameters that can be used to define a no track thermoplastic traffic marking were the CIELAB $\Delta E^{\ast }$ value and the CIE94 color tolerance $\Delta E_{94}^{\ast }$ . These two parameters were proposed by the International Commission on Illumination and have been used extensively for measuring color differences. As compared to other testing parameters, the change of these two parameters with time is more consistent and the selected no track thermoplastic traffic markings produced significantly lower $\Delta E^{\ast }$ and $\Delta E_{94}^{\ast }$ values as compared to the regular thermoplastic traffic marking. The research results have the potential to be used by decision makers to develop technical specifications to guide the real engineering applications of no track thermoplastic traffic markings.