Foxx made his comments about saving money by boosting the efficiency of existing transportation systems on a blog post on the Department of Transportation's website on Thursday.
The new secretary said that the department "has been getting better and better at improving the way we deliver the benefits of transportation to the American people."
Foxx touted improvements like the Federal Highway Administration's increased use of warm mix asphalt, which is designed to increase the speed of road projects being available for use.
"One tool in this initiative is Warm Mix Asphalt. And while that may not be a household phrase, but it's quietly saving taxpayers millions every year," Foxx said of the new concrete mixture.
"Warm Mix Asphalt is a new paving technology that allows asphalt to be produced and placed on the road at a lower temperature," he continued. "It uses less fuel, reduces emissions, and extends the paving season into colder weeks, which allows road crews to keep working longer."
Foxx predicted that "by 2020, we project that Warm Mix Asphalt will save more than $3.5 billion dollars — simply by using less fuel in the production and placement of asphalt."
Foxx said the Federal Transit Administration and Federal Aviation Administration (FAA) were also making improvements, citing the FAA's efforts to build a new satellite-based navigation for commercial airplanes that has been known as NextGen.
Foxx concluded that DOT's job "is to build even more momentum, to get even more out of every taxpayer dollar we are entrusted with."