We had electric busses in our city. They were awesome. The were far less noisy and didn't stink. But they were scrapped again. Reason: Diesel busses had a maintenance time of 2%, electric busses of 5%, meaning they spend 5% of their running time in maintenance. That was all, so we now have loud and stinky busses again.
That said, I don't think you can ever replace individual traffic. It is only possible in the most dense cities. Otherwise bus travel is too slow and unreliable for people working 40h+.
That said, I don't think you can ever replace individual traffic. It is only possible in the most dense cities. Otherwise bus travel is too slow and unreliable for people working 40h+.