Marple is a victim of geography (three roads in and out of the town towards where most people work) and being a nice place to live and bring up kids or retire to.
I see there being two ways to address the traffic situation, one tactical and within the purview of local and regional government. The other is strategic and requires a complete change in mindset from the population and led by central government.
Locally and regionally, we need to invest in mass transit to make it reliable, frequent and affordable. We need to give preference to mass transit over individually-owned vehicles and make public transport more appealing and more convenient. I know that's going to upset people who feel it their inalienable right to use their own car whenever they want, and politicians will be frightened of doing so, but the only way to get people off the roads is to give them a better alternative.
The second way requires a change in thinking. In my (probably completely inaccurate) estimate, I reckon that at least 40% of office jobs can be done remotely, at least some of the time. There are technologies that allow collaboration and communication to be done seamlessly from wherever you are in the world. I wish that the government hadn't invested in the massively expensive HS2 and instead used the billions to run fibre to every property in the country (and require new house-builders to do the same). With investment in virtual and augmented reality and research into collaboration technology, we could get a lot of people (knowledge workers, students, teachers etc) off the roads yet keep them productive. It also requires training for managers and owners to help them develop policies which allow their staff to benefit from remote working yet maintain productivity.
Yes, I understand that many jobs require a physical presence, but many don't, and a change in mindset and investment, would have a far more widely-reaching effect than just locally upgrading public transport.
Maybe I'm a pessimist (perhaps, pragmatist) but I can't really see anyone being brave enough to do either of these things properly.