How do exits get their numbers?
Most places number interchanges to the nearest milepost/kilometerpost. Some (in the U.S. and Canada: New England; NY; DE; some non-Interstates in FL; NS; and some other states’ toll highways) number their exits consecutively (1, 2, 3…). CA formerly didn’t number exits at all, except for some instances on freeways in Los Angeles, which were numbered by mile, apparently an isolated Caltrans experiment. Now exits on all state-maintained freeways will be numbered by mile (see http://www.dot.ca.gov/hq/traffops/signtech/calnexus/ for a list of numbers and http://www.dot.ca.gov/hq/paffairs/news/pressrel/02pr01.htm for a press release). I-19 in Arizona ( http://www.arizonaroads.com/interstate/i19.htm ) and DE 1 ( http://www.aaroads.com/delaware/sr1_turnpike.htm ) are numbered by kilometer, though I-19’s signs will be replaced by those with mile measurements as signs wear out starting in 2004 (see http://www.dailystar.com/dailystar/metro/6429.php ). Both practices of consecutive and distanced
