Road traffic speeds in other countries are indicated in kilometres per hour, while occasionally both systems are used. For example, in Ireland, a judge considered a speeding case by examining speeds in both kilometres per hour and miles per hour. The judge was quoted as saying the speed seemed "very excessive" at 180 km/h but did not look "as bad" at 112 mph; a reduced fine was still imposed on the speeding driver.
Miles per hour is the unit also used in the Canadian rail system, which uses km/h on roads.
Nautical and aeronautical usage
Nautical and aeronautical applications favour the knot as a common unit of speed. (One knot is one nautical mile per hour, with a nautical mile being exactly 1,852 meters or about 6,076 feet.)
In some countries mph may be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball.
^"Modern Living: Think Metric". Time Magazine. 9 June 1975. Archived from the original on 22 January 2011. Retrieved 15 June 2010. Meanwhile, the metricization of America is already taking place. Individual federal agencies, school systems, states and industries, as well as radio announcers, supermarkets, beverage bottlers and ballpark scoreboards, are hastening the everyday use of meters, liters and grams. ...a road sign outside Fergus Falls reads, ST. CLOUD 100 MILES OR 161 KILOMETERS. Other signs note that 55 m.p.h. equals 88 kilometers per hour.