Climate change scientists and many elected officials have recommended reducing greenhouse gas emissions by 80% by 2050. To achieve this level of reduction from the highway transportation sector AASHTO and others are considering several different strategies, including 1. increasing vehicle fuel efficiency; 2. shift to fuels or sources of power which produce lower GHG emissions or zero GHG emissions; 3. reduce the rate of growth inv vehicle miles traveled (VMT); and 4. improve highway operational strategies. A March 2009 report, NCHRP 20-24 (59) provided evidence that highway operational strategies can achieve 10-20% reductions in highway GHG, through a wide variety of different strategies, including both changes in how highways are managed and improved and changes in individual driver behavior. Research was proposed to support efforts to maximize operational strategies to reduce highway GHG, by (a) documenting a full range of operational strategies to reduce highway GHG, (b) indicating the circumstances and locales where these strategies could be most effective in reducing GHG, (c) providing quantitative estimates of their GHG reduction potential, both individually and in combination; (d) estimating their costs and cost-effectiveness; (e) identifying collateral benefits and dis-benefits; and (f) identifying policies and actions that could be taken to maximize their GHG reduction effect.  AASHTO leadership determined that other work by TRB and other organizations provided an adequate basis in 2011 for policy discussions and deferred indefinately further action on this research topic.