Slight Tangent: I've got a feeling that private vehicles in Zone 1 (and 2...) benefit a tiny percentage of the population, and should be the next target for reducing inner city congestion (implementation perhaps tricky).

Is this concept something you've come across in your work/field?

If not, any ideas for what is next? I hope to see:

1. Car free days over weekends in high streets.

2. Entire high streets converted to pedestrian, bus & bike only.

3. A move to a more bike/bus friendly city, see Utrecht [1]

[1] Utrecht: Planning for People & Bikes, Not for Cars https://vimeo.com/344373585