In the late 1970s, PennDOT saw its list of pavements requiring rehabilitation growing steadily and the State's transportation spending on pavement rehabilitation reaching historically high levels. User delays due to agency work zones were mounting. The department faced increasing internal and external requirements to demonstrate its good stewardship of public funds.
PennDOT recognized the importance of improving maintenance and rehabilitation practices with regard to the serviceability of its pavements and sought to provide the best pavement performance of the road network with the funds available. Pavements were designed according to standards of the American Association of State Highway and Transportation Officials (AASHTO); however, the pavement-type selection component of the design process was much less standardized. Pavement types were often selected on the basis of initial costs and expert opinion. As the list of backlogged pavement needs grew, the choice of paving material- ordinarily within the purview of the design engineer-was becoming a source of contention within and outside of the department.
PennDOT wanted a means to select pavement types that would meet both the initial and long-term performance requirements for a project. The goal was to determine what the total cost implications were for its pavement decisions. The department wanted to ensure that each project could fulfill its life-cycle performance requirements for the lowest cost.
|Until the mid 1980s, PennDOT selected pavement types on the basis of initial cost and expert opinion. With growing investment requirements, decisions about paving materials were becoming a source of contention.|
PennDOT recognized the disruptive effects that construction work zones can have on road users. Road construction work zones cause delay and increase vehicle operating costs. PennDOT also understood that its pavement decisions would be scrutinized by the legislative and executive branches of the State government, the paving industries, and the public at large.
PennDOT identified LCCA as an analytical tool that could meet its needs. By requiring explicit consideration of all costs incurred during the life of a project, LCCA is able to identify the lowest total-cost alternative to meet the performance requirements of the project. By quantifying work zone user delay, LCCA includes the effects of work zones on road users. Finally, documentation of the assumptions made and inputs used in the LCCA provides the means to communicate PennDOT's decision rationale to interested stakeholders.