B1 Road is a major road in Kenya connecting Nakuru to the Ugandan border. The road can be divided[by whom?] into two distinct parts: Nakuru - Kisumu highway and Kisumu-Busia highway.
The eastern end of the road begins from Mau Summit east of Nakuru, where it diverts from to the A104 road (Nairobi to Uganda via Eldoret). The section between Ahero and Kisumu is common with A1 road.[1]