Electric or hydrogen fuel cell cars will eventually become the norm, but it will take decades for petrol and diesel engine cars already on the roads to disappear.
Here's my forecast.
Sales tax will either be increased on new petrol cars or reduced for new electric cars steering the choice of which new car to buy towards electric.
MOT emission standards will rise, putting many older cars off the road.
Diesel engines in lorry's will have to meet more stringent emissions standards, but there will be no mandatory change to electric as electric simply does not have the range needed for commercial goods vehicles.
Taxes on petrol and diesel will increase and there will be more stringent environmental controls put on petrol and diesel storage, putting petrol stations out of business because it will be uneconomic to bring the station up to code along with the declining demand.
Sections of the motorway will be designated as electric vehicles only, maybe city centers will also be included.
All vehicles will have speed limiters ending the sale of high performance cars and bikes.
The perfection of autonomous vehicles may end cars as we know them completely, as the prospect of summoning an autonomous car to take you to the shops and then summon another to bring you home has so much appeal. No costs of owning, maintaining, insuring or parking a car. No drivers license needed and no chance of a drunk driving or speeding arrest.
Cars will go back to being a device for transportation again, nothing more.