Green Contracting in Highway Construction: State of Practice

Growing public awareness of climate change requires transportation professionals to integrate green concepts into the transportation planning, design, construction, and operation processes. For the past decade, while many studies have been done regarding carbon emission reduction strategies for on-road and off-road operations, very few have dealt with emission reduction issues in highway project delivery. This paper, based on a survey of 39 State Departments of Transportation, reports the green contracting practice for delivering highway projects in the U.S. Four levels of green contracting strategies and their application procedures are identified. Organizational reasons for successful implementation of green contracting are presented and discussed. More importantly, the study discovers there is a substantial lack of consistent methodology and processes for implementing green contracting. Nor is there a common vocabulary in this field. In an effort to promote green contracting in highway construction, the study suggests that state highway agencies, 1) establish organization-wide green initiatives; 2) develop green specifications and standards; 3) encourage broader industry participation