Decision Models to Support Greenhouse Gas Emissions Reduction from Transportation Construction Projects

Abstract

In this paper, an optimization-based methodology is proposed to permit a construction firm to assess its equipment needs while accounting for the GHG emissions resulting from equipment use and policy makers to set carbon price, caps, and penalties for noncompliance. Specifically, the problem of optimally selecting equipment for project tasks to simultaneously minimize emissions and project costs given project duration, workload, compatibility, working conditions, equipment availability, and regulatory constraints is formulated as a multiperiod, biobjective, mixed integer program (MIP). Two techniques are considered for its solution: a weighting technique, which seeks to create the Pareto-frontier, and a constraint approach whereby costs are minimized while maintaining an emissions cap. Off-the-shelf MIP solvers, such as CPLEX, can be used to provide solutions once the model input data and parameters are specified for a particular application. These techniques are applied on a case study involving construction of a roadway in Maryland. The developed approach is generic and can be applied over varying geographic locations, site elevations, soil properties, and other factors that affect equipment operation and productivity.