Oliver Keating wrote:

Everyone considers their journey to be "important" or even
"essential". But the proof of the pudding is whether they are
prepared to pay for it.

I always assumed the selling point of the M6 Toll was similar to First Class
on the trains. You pay over and above the standard price to get a better
quality of service - in the case of the M6 Toll this is a less congested
route around the M5/M6 interchange and it's associated hassles. Those who
see this as something worth paying to avoid will do so, in just the same way
that certain people prefer to travel First Class on the trains...

The M6 Toll is nothing to so with congestion reduction per se, merely a
commercial venture allowing people a higher quality alternative to the
congested public route through Birmingham