Maybe it's different over there.
Toll roads here are a washout. The M6 Toll is substandard and losing money fast. It'll lose a lot more a lot faster when it comes time to renew the surface and upgrade the technology on it. It's also gone up in price; a fiver to drive 26 miles is taking the mickey, quite frankly.
Read the numbers carefully. A reduction of 60,000 vehicles in six months sounds like a lot. It's not; it's a diddly 330-ish vehicles a day. In practical terms, it's made piss-all difference to driving in central London. Everyone who was there had to be there anyway; the difference is that now TfL make a lot of money out of running the CC scheme, and the buses are still shit.
TfL are very, very good at using extrapolations to "prove" that the CC is doing good. A simple drive across central London would tell you different.