The Teslas join a 350-car fleet, DOT deputy director Ed Sniffen told the station.
"We got 43 Teslas on this initial offering," Sniffen said. "The best price we received from the vendor was for the Model Y."
Under a new system, DOT won't own the vehicles or have to pay maintenance.
"Those vehicles, if we look at 4,800 miles driven annually, it is going to cost us just under $7,000 per vehicle per year," Sniffen said.
The Teslas will be work vehicles for inspectors and technicians.
"There is a definite fuel cost we are getting savings on," Sniffen says. "There is also replacement costs that we are getting savings on, and there is CO2 emissions that we are getting savings on," said Sniffen.