The other points you raised may be valid, but don't mean that the technology shouldn't be developed. Lots of stuff could be used as a weapon, developing it properly means trying to prevent that, but not just giving up on things because of potential misuse. I'd like to hope that any redesigns of space to accommodate self driving cars would benefit cyclists and pedestrians. Those in the cars would likely already be getting everywhere faster, especially at peak times due to better traffic management, actual higher speeds seem unnecessary in an urban environment.
The other points you raised may be valid, but don't mean that the technology shouldn't be developed. Lots of stuff could be used as a weapon, developing it properly means trying to prevent that, but not just giving up on things because of potential misuse. I'd like to hope that any redesigns of space to accommodate self driving cars would benefit cyclists and pedestrians. Those in the cars would likely already be getting everywhere faster, especially at peak times due to better traffic management, actual higher speeds seem unnecessary in an urban environment.