Using LEED strategies in transportation facilities can help save project stakeholders significantly and lead to a higher return on investment. The operating costs of green buildings, according to a 2012 study from McGraw Hill Construction, dropped 13.6% for new construction and 8.5% for existing projects. LEED-certified buildings saw a 19% decrease in overall operating costs compared with similar, non-certified buildings. In 2010, the transportation industry accounted for 14% of all greenhouse gas emissions, making it the fourth most contributor. In the U.S. transportation took the number two slot for greenhouse gas emissions, accounting for 27% in 2015.