Life cycle analysis of different pavement marking types for durable materials.

摘要

This particular research is focused on determining the life cycles of various pavement markings types, i.e. (Skip, Center, and Edges) of current durable pavement marking materials, i.e. inlaid tape and thermoplastic. The basic factors considered for this analysis were cumulative precipitation, cumulative snowfall, and cumulative traffic volume along with the retroreflectivity data collected by State highway Administration. This data was collected at six locations all over Maryland. The data was analyzed using a statistical software tool (SPSS) to conduct regression analysis and predict the life cycles. Four mathematical equations were used to determine the best model that would fit the overall data and define the relationship between these variables. These equations were used to generate the graphical outputs of the retroreflectivity performance. To give a better depiction, the overall output was represented in to nine different cases which were categorized based on the traffic and snow conditions i.e. (Low, Medium, and High). The R square value was used to ascertain the best model function. The linear function had the highest R square value among all the other equations, thus giving a best fit for the data collected and the variables used as input. Due to limited and inconsistent nature of the field data, some functions had lower R square values. The white skips and edges had a higher adjusted R square value than edges and centers for yellow markings. All types' skips, edges, and centers for thermoplastic and inlaid tape performed better under lower traffic and lighter snow conditions. Thermoplastic yellow center had very low R square values, and so did inlaid tape yellow center with shorter life cycles. Overall white skip had a longer life cycle than white edges for both materials, while yellow edges had a better life cycle than yellow center for both materials. Each marking type had a different life cycle resulting from one reaching the threshold value earlier than the other. The striping and installing of the marking types in two cases which are restriping all types with one or more types having a decent life cycle left, and restriping only one particular type marking which becomes ineffective, were found to be expensive in terms of the overall costs incurred. Thus this research tries to suggest suitable options so as to obtain uniform life cycles for all types so that they could be restriped and installed together, rather than one at a time after each type reaches its respective threshold value.