[Pseudoscience-is-malarkey (OP)]

?

[alancalverd]

Yes, several.

Some are ancient private bridges that have been incorporated into public roads, with very small historic tolls collected almost as a token to prove ownership of the land, but most are privately-financed major constructions such as the Thames and Severn  bridges and tunnels, built specifically to carry modern (free) motorways. There is also a significant "M6 toll" motorway that bypasses Birmingham, originally intended to divert heavy goods traffic but the truck tolls are high and the speed limit low, so most trucks use the shorter, free, M6 where they can maintain 50 - 60 mph over the city anyway, and the rural toll road is almost entirely populated by cars and motorbikes.   

[Petrochemicals]

The severn bridge is now free, but it used to be toll in one direction only, you had to pay for the privelidge to leave england

https://en.m.wikipedia.org/wiki/Severn_Bridge

[syhprum]

I have to pay £5.0 to go to Essex unless I go a long way round !

[Bored chemist]

http://www.merseygateway.co.uk/

[skimthought]

Yes. There are at least 23 toll roads in the UK, and 18 of which are river crossings. Toll roads or tolls are public roads that charge drivers a fee for its use. While on a toll road, you will have to pay in order to continue driving along it, to cross a bridge or reach a particular destination.

[Colin2B]

While on a toll road, you will have to pay in order to continue driving along it, to cross a bridge or reach a particular destination.

I don’t understand this. You pay to get on, but once you are on you don’t pay more.

[alancalverd]

That depends. The M6 toll, for instance, is cheaper if you exit part way along than if you use the whole road length.

However I do not recommend leaving a toll bridge before the end - false economy.