'Zoom level 1': National JTS/planning data

[Robinlovelace]

Split out from #11:

Data that we already have access to:

• Existing planning application data (e.g. number of large applications per LSOA zone based on data released by @aspeakman)
• PCT data, e.g. with summary statistics on quietness diversion factor at the LSOA level
• JTS data

While working on a demo of #16 I have come to realise that the JTS datasets are huge with dozens of variables across 8 services, 4 years, 3 modes and 2 main levels of geographic aggregation (LA/LSOA).

Of those I think the 'time' variable in the 2017 versions of the 8 main destination types are most important.

However, I think the data is large enough to warrant a stand alone mini-app based on the principle of modularity and for people who just want JTS data (and not the other datasets visualised by the ActDev app/apps). I think that this could represent a starter for 10 on the UI elements of such a JTS visualisation platform: https://apps.saferactive.org/actdev-shiny-demo/

See also: https://www.nao.org.uk/other/transport-accessibility-to-local-services-a-journey-time-tool/

It's possible that that tool was inspired by our work on Acton.

[Robinlovelace]

One thing to note, we do not want to duplicate this work. It seems to me they focus on 'N. journeys out of 7' rather than average time:

[Robinlovelace]

That differs from the emphasis of our UI on average time (although that's not shown yet):

[Robinlovelace]

This is split-out from #12