Within the central area, walking is usually the best idea as one-way systems make bus routes confusing. Expect some routes to change significantly if and when the big new Angara bridge is completed.
Frequent marshrutka 20 runs from the airport, up ul Dekabrskikh Sobyty, ul Karla Marksa and ul Lenina before passing the Hotel Angara and crossing to the train station. Trolleybus 4 (R5) takes a similar route but via ul Sovetskaya and Hotel Gloria.
From the train station trams 1 and 2 run to uls Lenina and Timiryazeva, while bus 7 crosses to pl Kirova, then loops round the centre and out past the Znamensky Monastery. Bus 16 continues down ul Lenina, past the Raising of the Cross Church and (eventually) the Angara Dam. It then passes within 500m of the SibExpo hotels before looping back beside the Raketa hydrofoil station to the Angara steamship. Slow tram 5 from the Sun Hotel trundles to the central market, and from here tram 4 goes past the bus station and Kazansky Church.
For the west bank, both bus/marshrutka 3 from the central market and marshrutky 12 and 72 (to Solnichny) from the train station cover the whole length of ul Lermontova.