New Transportation chief urges safety on Fourth of July

"For example, during the Independence Day holiday in 2011--another long weekend--428 people were killed in crashes," the new secretary continued. "Many of those crashes--38 percent of them in 2011--involve an alcohol-impaired driver. These crashes are entirely avoidable."

Foxx said it was important for holidays travelers to be mindful of other revelers who might be celebrating outdoors.

"Whether you’re driving to a cookout or to catch the fireworks, please take care to drive safely and to celebrate responsibly," he wrote. "Millions of families will be celebrating outside, making it especially important to focus on the road." 

Foxx was sworn in as the 17th U.S. Transportation secretary on Tuesday afternoon.

He has taken over for former Rep. Ray LaHood (R-Ill.), who had served as Transportation secretary since 2009.