The Rwandan government has increased investment in the transport infrastructure of Rwanda since the 1994 genocide, with aid from the United States, European Union, Japan, and others. Kigali is the centre of the country's road network, with paved roads linking the city to most other major cities and towns in the country. It is also connected by road to other countries in the East African Community, namely Uganda, Tanzania, Burundi and Kenya, as well as to the eastern Congolese cities of Goma and Bukavu; the most important trade route for imports and exports is the road to the port of Mombasa via Kampala and Nairobi, which is known as the Northern Corridor. Within the city there was a total of of road in 2012, although only fourteen per cent of this was paved road and many of the unpaved sections were of poor quality and dangerous during rainfall. The authorities have been making gradual improvements since the 1990s, increasing the quality of the surfaces and also upgrading most of the city's arterial routes to dual-carriageway.