Washington, D.C. — Travelers planning trips involving Mexico City face uncertainty after the U.S. Department of Transportation revoked approval for 13 routes operated by Mexican airlines.

 WASHINGTON — The U.S. Department of Transportation has yanked approval for 13 existing or proposed routes operated by Mexican carriers, an unprecedented move that could alter travel plans for thousands of leisure and business passengers moving between Washington and other U.S. gateways and Mexico City.