The OECD has published a fairly realistic report about the effects of self-driving cars on urban transportation. However, the report contains some implicit assumptions that may not come true.
“Single-occupancy car use generates individual and collective benefits,” admits the report, “but these are eroded and, in some cases, obviated by environmental impacts, loss of transport system efficiency due to congestion, social inequity and exclusion, as well as road crashes and strong dependence on fossil fuels.” Except for congestion, however, most of these problems are exaggerated and even congestion is technically easy (but politically difficult) to solve with congestion pricing.
“Typically, the response to the negative impacts of car-dominated transport systems,” continues the report, “has been to promote public transport.” But this “comes at a heavy cost,” and despite many cities paying that cost, “public transport continues to lose market share to private vehicles in most developed economies.”