The following highways are numbered 278:
Canada Manitoba Provincial Road 278
Japan Japan National Route 278
United States Interstate 278 U.S. Route 278 Arkansas Highway 278 (former) Florida State Road 278 (former) Georgia State Route 278 K-278 (Kansas highway) Kentucky Route 278 Maryland Route 278 (former) Minnesota State Highway 278 (former) Montana Secondary Highway 278 New Mexico State Road 278 Nevada State Route 278 New York State Route 278 Ohio State Route 278 Pennsylvania Route 278 (former) Tennessee State Route 278 Texas State Highway 278 (former) Texas State Highway Spur 278 Farm to Market Road 278 (Texas) Utah State Route 278 (former) Virginia State Route 278 Washington State Route 278