Development of traffic data input resources for the mechanistic empirical pavement design process.

The Mechanistic-Empirical Pavement Design Guide (MEPDG) for New and Rehabilitated Pavement Structures uses
nationally based data traffic inputs and recommends that state DOTs develop their own site-specific and regional
values. To support the MEPDG NCDOT needs site-specific truck classification counts, truck axle load spectra
regional average seasonal adjustment factors, and forecasting methods for truck class volumes. This research
proposal addresses these NCDOT traffic data and forecasting needs for implementing the MEPDG.
The research produced the following results: (1) software to process and clean WIM data; (2) database of high
quality, clean NCDOT vehicle class counts and weight data; (3) simulation studies to guide the selection of
sensitive traffic data and traffic count locations; (4) techniques for traffic data clustering and seasonal analysis of
vehicle classification and truck axle loadings; (5) software to prepare datasets and sampling plans for Levels 1, 2
and 3 MEPDG requirements (Level 1 site specific, Level 2 seasonal groupings, and Level 3 statewide averages); (6)
site specific, regional and statewide NC traffic data inputs for Levels 1, 2, and 3 in the MEPDG procedures for
vehicle class distributions and axle load spectra including seasonality; (7) vehicle class forecasting methods for
MEPDG procedures; (8) case study demonstrations and analyses; and (9) implementation and management plan for
MEPDG traffic data.