Gibraltar has a limited public transportation system, due to the compact size of the territory. Gibraltar has 49.9 kilometres (31.0 mi) of highways, all of which are paved. It has one of the highest levels of per capita car ownership in the world, with as many motor vehicles as people. Unlike the rest of the United Kingdom, traffic in Gibraltar drives on the right, as it shares a land border with Spain. (Gibraltar is not in the United Kingdom). Traffic formerly drove on the left; the change to driving on the right was made at 5.00 a.m. on 16 June 1929.Older roads in Gibraltar, primarily in the city centre, are fairly narrow with a typical speed limit of 50 km/h (31 mph). Gibraltar has ten fuelling stations, and fuel prices are lower than in neighbouring Spain. Some people from Spain even enter Gibraltar for the sole purpose of filling their cars’ fuel tanks. Gibraltar’s international vehicle registration is GBZ, and Gibraltar car number plates consist of the letter 'G' followed by up to five digits (1-99999) or four digits (1000-9999) and a single letter. These are as standard, the same shape, type face and colours as those in the UK, however non-standard number plates have been permitted. The Chief Minister’s official car has the registration number G1, while the Governor’s car, following tradition, has a crown, in place of a number.