I don't see this happening in the near future. Congress hasn't done much of anything for the last four years and this isn't likely to get a consensus. Once autonomous cars are on the road I can see a need to ensure that they can be sold in all states, but before then it's mostly about testing, which isn't a compelling reason for moving legislation.
Cynically this looks like politicians wanting money and legislative types needing to show they are earning their paychecks.
Cynically this looks like politicians wanting money and legislative types needing to show they are earning their paychecks.