And it doesn't involve impossible technologies or driving foreign mini cars:
BENEFITS OF EXCELLENCE IN TRAFFIC SIGNAL OPERATIONS
Traffic signal operations must be viewed as a continually evolving process with the ultimate goal of improving the level of operations nationwide. If the nation supported its signals at an A grade level, quality of life and protection of the environment would benefit significantly, including:
• Reductions in traffic delay ranging from 15–40 percent; reductions in travel time up to 25 percent; and reductions in stops ranging from 10–40 percent.
o For example, a driver who spends two hours in the car commuting to and from work and running errands would save 117.5 hours per year as a benefit of improved signal timing.
• Reductions in fuel consumption of up to 10 percent.
o A driver who uses one tank of gas a week would save five full tanks per year per household, or approximately $240.14 Nationwide, this would amount to a savings of almost 17 billion gallons of motor fuel per year.
• Reductions in harmful emissions (carbon monoxide, nitrogen oxides and volatile organic compounds) up to 22 percent.
Note: Spending less than 1 percent of the total expenditure on highway transportation would lead to a level of excellence in traffic signal operations. This investment strategy would leverage an investment with a 40:1 benefit-cost ratio and would result in benefits of as much as $45 billion per year. This corresponds to a price of less than $3 per U.S. household resulting in savings of $100 per household per year.
For the full 2007 National Traffic Signal Report Card, see