Highway design study phase I : the model

The Highway Design Study focuses on the interrelationships among construction costs, road maintenance costs and vehicle operating costs with the objective to improve decisions on design standards of low volume roads. Phase I of the study provides a methodological framework which delineates the underlying engineering relationships in a prototype simulation model. The Highway Design Model incorporates three functional submodels: construction, roadway maintenance, and vehicle operation. Each submodel estimates resources consumption first and calculates the money cost of those resources using prices separately specified. Hence, the model is adaptable to any ecomony regardless of relative costs of different resources. Construction costs are estimated for specified design standards in a given environment using productivities of equipment packages. The maintenance submodel predicts the deterioration of the roadway surface as a function of the original construction standards, the specified maintenance policy, and traffic volume. Vehicle operating costs are then predicted as a function of the roadway condition and the vehicle characteristics. Thus the model can be used to examine the tradeoffs among construction standards, maintenance standards, and vehicle operating costs.