The following highways are numbered 603:

Canada

Alberta Highway 603 The Canadian province of Alberta has provincial highway network of nearly as of 2009, of which were paved. All of Alberta's provincial highways are maintained by Alberta Transportation (AT), a department of the Government of Alberta. The n ...

Ontario Highway 603 This is a list of secondary highways in Kenora District, most of which provide access to isolated and sparsely populated areas in the Kenora District of northwestern Ontario. Highway 525 Secondary Highway 525, commonly referred to as Highway 5 ...

Saskatchewan Highway 603 Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

Costa Rica

National Route 603

United States

* * * * * {{Road index, 603