The transport system in Greenland is very unusual in that Greenland has no railways, no inland waterways, and virtually no roads between towns. Historically the major means of transport has been by boat around the coast in summer and by dog sled in winter, particularly in the north and east. There are no roads between settlements, only within them and around them. There are 150 km (90 mi) of roads in the whole country; 60 km (40 mi) of the roads are paved. The roads are primary or local roads, there are no highways in Greenland. Speed limit ranges from 50 kilometres per hour (31 mph) for local roads to 80 kilometres per hour (50 mph) on primary roads. Some farms in the south have fairly extensive very simple roads for terrain vehicles (not included in above figure), used for sheep farming and hay collection. There are plans for a 170-kilometre-long (110 mi) road between Sisimiut and Kangerlussuaq, discussed for several years but still not decided (as of 2013).