(02 Aug 2021, 10:13 am)JP6004 wrote My point is the gateshead borough is defined as one zone, travelling from outside of this zone, say from Chester or Washington would naturally cost more

Why does the dashed zone boundary line on the map not divide Gateshead and Newcastle then? 

By bonding Gateshead and Newcastle together on a map, and not dividing them by any clear boundary, creates ambiguity and leaves it open to customer interpretation.