Saint Pierre and Miquelon has no railway, it has 114 km (71 mi) of highways plus 45 km (28 mi) of unpaved roads. Its only major harbour is at Saint-Pierre although there is a smaller harbour at Miquelon. The dependency has no merchant marine and two airports; the runway at Saint-Pierre Airport is 1,800 metres (5,910 ft) long, and at Miquelon Airport, 1,000 metres (3,280 ft). Saint Pierre and Miquelon uses standard French vehicle registration plates, rather than issuing plates in the format of six inches high by twelve inches wide used by all other jurisdictions in North America. However, the islands do not follow the standard French numbering system. Until 1952, cars were simply numbered from 1 onwards, without any code to identify them as being from Saint Pierre and Miquelon. Beginning in 1952, they had serial numbers followed by the letters SPM, e.g. 9287 SPM. Since 2000, all numbers have begun with the letters SPM followed by a serial number and serial letter, e.g. SPM 1 A. Vehicles are mainly French or European. North American vehicles can also be found in recent years. Road signs are in French and are European influenced.