The following highways are numbered 340:
Canada Manitoba Provincial Road 340 New Brunswick Route 340 Newfoundland and Labrador Route 340 Nova Scotia Route 340 Prince Edward Island Route 340 Quebec Route 340 Saskatchewan Highway 340
India National Highway 340 (India)
Japan Japan National Route 340
Norway
United Kingdom A340 road, Basingstoke, Hampshire to Pangbourne, Berkshire
United States U.S. Route 340 Arkansas Highway 340 Colorado State Highway 340 Georgia State Route 340 (former) Hawaii Route 340 Indiana State Road 340 Missouri Route 340 Nevada State Route 340 New York State Route 340 Ohio State Route 340 Pennsylvania Route 340 Texas: Texas State Highway 340 (former) Texas State Highway Loop 340 Wyoming Highway 340