Green Contracting in Highway Construction State of the 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, although many studies have been done on carbon emission reduction strategies for on-road and off-road operations, few studies 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 United States. 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 important, 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 (a) establish organizationwide green initiatives, (b) develop green specifications and standards, and (c) encourage broader industry participation.