Since the collapse of the Nigerian railway system, the transportation of cargo relies mainly on road transport. This form of transportation tends to be much more expensive and hampered by the bad quality of roads, it currently accounts for over 80% of all traffic intra-and inter-city. In addition, the country has almost 1,000 kilometres of coastline which accounts for 68% of total seaborne trade in West Africa. Many loaded cargoes arrive daily to help supply the Nigerian economy heavily dependent on imports. Domestic air transport is limited to large cities.