Tiers should be determined by local Council/District rates, data for which is readily available (https://coronavirus.data.gov.uk/details/interactive-map) This information could be made available on the NHS app and by third party mapping apps so people can see clearly which area their homes are in.
You may be interested in these active petitions
The overly restrictive Covid tier rules that lump areas with low Covid rates in with areas with high rates is not sensible.
The economy, Nation and health system needs rules that are proportionate to local Covid rates.