Trains, Trains, Trains.<p>Get real. First off they cost so much more per mile they already bust the bank and then comes maintenance. Finally the end is they cannot respond to population movements.<p>Light rail is already a boondoggle of an expense in many cities trying to fit them in, with per passenger costs so many times that of alternate solutions only a politician could love it.<p>Trains are a romanticism that blinds people to their real cost. Heavy rail has many uses and sharing tracks can be a good solution. However when new heavy rail is proposed they don&#x27;t want to take into account existing support infrastructure, they want to build all new end points; here is a hint start and end at an major airport where taxis and buses already provide service and parking is plenty<p>As for the safety canard, we don&#x27;t have enough history on autonomous cars and buses with proper planning to make that call. If you  want to even the playing field, instead of making a new train track you instead use that same space for dedicate autonomous vehicle travel. In this you can let cars and buses serve the same central points and at the end of the route there is no need to change vehicles. Bonus, no trains or tracks to maintain!