I think this is a clever option. It looks a little slow, but when there is a traffic jam, it just keeps chuggin along. Cheaper than building an elevated mono rail. The positive and negative leads (steel wheels?) are widely spread. The graphic looks like CGI, but the youtube in the link seems real.
http://www.citylab.com/tech/2016/05...raddling-bus-finally-become-a-reality/483953/
http://www.citylab.com/tech/2016/05...raddling-bus-finally-become-a-reality/483953/