WASHINGTON (Reuters) – The U.S. Transportation Department said Friday that 3,700 employees had been temporarily furloughed after Congress failed to reauthorize surface transportation programs before a deadline that expired early Friday.

A department spokesperson said the agency is “taking every step we can to mitigate the impacts of this temporary lapse in authorization.” Safety critical employees are exempt from the furloughs. Aides said U.S. lawmakers are considering a 30-day surface transportation extension as negotiations continue over a pair of infrastructure and spending bills.

(Reporting by David Shepardson)