It will revolutionise driving, that's for sure. The petrol will...

It will revolutionise driving, that's for sure. The petrol will tax will need to be replaced, no doubt about that.

I share your view that it will by default probably reduce congestion. One of the features of it is that because it's electronic, it will be a dynamic tax that changes price depending on the road and time. E.g. If it is more expensive to be on a city freeway during peakhour, it will encourage ride sharing or other strategies.

It's going to be an important part of this whole ev/driverless car revolution. Congestion should reduce, accidents should reduce, efficiency for business should go up thus there should be a large amount of money freed up for other things.

The downside is that it could be used by governments for revenue raising for other purposes. Like election campaigns.

P.S. Just heard that Tesla is going to close it's retail stores and just offer an online store only. More evolution of the car industry.