BACKGROUND : The Mechanistic Empirical Pavement Design Guide, recently developed under NCHRP Project 1-37A (http://www.trb.org/mepdg/guide.htm), presents the broad issues involved in pavement type and strategy selection. These issues include engineering considerations (e.g., roadway/lane geometrics, roadway foundation, and roadway peripheral features); traffic considerations; environmental considerations; construction considerations (e.g., availability of local materials or contractor capabilities, recycling, and conservation of materials and energy); other considerations (e.g., performance of similar pavements in the area, adjacent existing pavements, traffic safety, incorporation of experimental features, stimulation of competition, and recognition of local industry and local government preferences); and economic considerations (e.g., life-cycle cost). However, this Guide does not identify specific procedures for comparing alternatives and making selections. Also, recent developments in construction practices, contracting approaches, material utilization, and other factors are expected to influence the selection process and should be considered.
The pavement-type selection process traditionally uses life-cycle cost analysis (LCCA) concepts to model the cost of pavement alternatives during a performance period. However, some state departments of transportation (DOTs) have begun developing processes that provide for selection of pavement type or other highway materials through the bid process. The selection process is then accomplished through the alternate design/alternate bidding (ADAB) procedure that allows the bidding contractors to select the pavement type that will be constructed. There are several forms of pavement selection processes but they have not been well documented. Also, concerns have arisen in recent years regarding the effectiveness and equity of pavement-type selection processes. Research is needed to identify current practices, review relevant information, and develop rational processes that consider all relevant factors and thus provide a realistic means for pavement-type selection. Also, there is a need to prepare a Guide for Pavement-Type Selection to facilitate use of these processes. Such a Guide will help highway engineers and administrators with the task of pavement-type selection.
OBJECTIVE: The objective of this research is to develop a Guide for Pavement-Type Selection. The Guide shall include processes for consideration in making decisions regarding pavement-type selection as well as agency-based (decision is internal to the highway agency) and contractor-based (selection is made by the contractor using criteria stipulated by the agency) processes.
Status: The project is complete. The final report has been published as NCHRP Report 703,
available at http://www.trb.org/Main/Blurbs/165531.aspx