The following highways are numbered 315:
Canada Manitoba Provincial Road 315 New Brunswick Route 315 Prince Edward Island Route 315 Quebec Route 315
China China National Highway 315
Costa Rica National Route 315
India National Highway 315 (India)
Japan Japan National Route 315
United States Interstate 315 (unsigned) Arkansas Highway 315 Connecticut Route 315 Florida State Road 315 (former) Georgia State Route 315 Iowa Highway 315 (former) Kentucky Route 315 Louisiana Highway 315 Maryland Route 315 Maryland Route 315 (former) Mississippi Highway 315 Montana Secondary Highway 315 New Mexico State Road 315 New York: New York State Route 315 County Route 315 (Erie County, New York) Ohio State Route 315 Ohio State Route 315C (unsigned) Pennsylvania Route 315 South Carolina Highway 315 Tennessee State Route 315 Texas: Texas State Highway 315 Farm to Market Road 315 Utah State Route 315 Vermont Route 315 Virginia State Route 315 Wyoming Highway 315
Other areas: Puerto Rico Highway 315 U.S. Virgin Islands Highway 315