The following highways are numbered 604:
Canada Alberta Highway 604 Ontario Highway 604 (former) Saskatchewan Highway 604
Costa Rica National Route 604
United States
County Route 604 (Atlantic County, New Jersey) County Route 604 (Burlington County, New Jersey) County Route 604 (Camden County, New Jersey) County Route 604 (Cape May County, New Jersey) County Route 604 (Cumberland County, New Jersey) County Route 604 (Essex County, New Jersey) County Route 604 (Gloucester County, New Jersey) County Route 604 (Hudson County, New Jersey) County Route 604 (Hunterdon County, New Jersey) County Route 604 (Mercer County, New Jersey) County Route 604 (Middlesex County, New Jersey) County Route 604 (Morris County, New Jersey) County Route 604 (Ocean County, New Jersey) County Route 604 (Passaic County, New Jersey) County Route 604 (Salem County, New Jersey) County Route 604 (Somerset County, New Jersey) County Route 604 (Sussex County, New Jersey) County Route 604 (Union County, New Jersey) County Route 604 (Warren County, New Jersey)
Farm to Market Road 604