Fuel pricing won't work
Whilst the idea of fuel pricing is attractive to control vehicle journeys the reality is the biggest fuel users are essential such as delivery lorries/ buses/taxi's etc. So it will just raise everyday prices for everyone.
Also note what happened when diesil hit 1.30/litre. Theft went through the roof around here.
So to reduce congestion make public transport attractive with joined up thinking. Buses that meet up with trains . Bus/ train routes that are affordable to use. For me to go to Leeds and back from Wolverhampton costs £45 about the same as the diesil in a car. For 4 of us to go to leeds costs 4 times as much by train but the same by car.
Work from home more. That will be the best solution but this means company management accepting differing work practices.