Surveys performed in Seattle, Washington and Boston, Massachusetts indicated 50 percent of travelers changed their travel route and 45 percent changed their departure time as a result of better traveler information. In addition, 5 to 10 percent of travelers changed their travel mode based on better traveler information.
The impact of traveler information on emissions in Boston was calculated based on an assumption that 30 percent of all daily callers would changed their travel plans as a result of Smart Traveler information. The derived data was input into the EPA MOBILE5a emissions model in order to estimate impacts "with" and "without" traveler information. On a daily basis, the adjusted travel behavior reduced volatile organic compounds by 498 kilograms (25 percent), reduced NOx by 25 kilograms (1.5 percent), and reduced CO by 5,032 kilograms (33 percent). While these estimates were significant for participating drivers, they represented only 28,800 daily trips in the Boston metropolitan area which had 2.9 million registered drivers.