The zoning thing is interesting. Although I think the idea the zones should be strictly geographic is out dated. The zones exist to increase pricing for travel

The zoning thing is interesting. Although I think the idea the zones should be strictly geographic is out dated. The zones exist to increase pricing for travelling though congested parts of the network, and provide cheaper fares for people that avoid them. Historically the busiest part of London was just the centre. But the cites evolved quite a bit, and now has multiple busy spots like Canary Wharf, Shoreditch and soon Battersea. So it makes sense to put them in zone 1 from a traffic density perspective.