My commute is 23km one way, 100% on road (though almost all roads have a barrier-separated bike lane, and the ones that don't typically have low traffic). Most of the roads are well paved, though there are a few that are quite bumpy. Shanghai topography is extremely flat, so there are no hills to speak of. Highways in the central city are elevated, so I don't have to worry about crossing them. My commute involves a 10 minute long ferry crossing of the Huangpu River, which costs 1.3RMB (~20 cents) each way, as bikes are not permitted on bridges or in tunnels in Shanghai.