Accessibility of Welsh schools by public transport – visualised

A commission from the Welsh Government has resulted in new functionality for Mapumental, which now has the capability to display multiple points and to produce RAW data compatible with GIS applications. Here’s how it happened.

Bws Ysgol - Image by Aqwis via Wikimedia, CCHow accessible is your nearest school, post office, or GP’s surgery? In Wales, that’s not always a simple question: the country’s mountainous landscapes, rural populations, and sometimes infrequent bus services can mean that those without cars are rather cut off from public service provision.

But of course, like any other authority, the Welsh Government has an obligation to quantify just how accessible their services are.

For many years, they have done so using a number of different methods. Some of these involve literally millions of point to point calculations – so, naturally, when Bill Oates, Head of Geography & Technology, Knowledge Services at the Welsh Government, approached Mapumental, he was keen to discover whether we could simplify things.

We were keen to try it, too – plotting multiple points would add a whole new slew of possibilities to Mapumental. Previously, Mapumental has been all about travel from a single point, and this functionality would bring new applications across all kinds of industries and users.

There’s only one way to find out

The sensible way forward was to pick a single service and see what we could do. One of the government’s open data sets showed positioning of all the secondary schools in the country, and would give us a very good indication of how manageable the task would be across all other provisions.

So we set ourselves this aim: to display the shortest transit time to get to any secondary school in Wales, from any point in that country.

This project was not like the map we made for the Fire Protection Association last year, with its postcode input and interactive sliders. It bore more relation to our static maps, but with the additional dimension that the single map would have multiple points plotted on it. Each point would display its own associated journey times, and where travel to one school was quicker than to another, it would have to override the data of the school that was further away.

And here’s the (very pretty) result

Welsh secondary schools travel times mapTransit times by public transport to secondary schools in Wales, with an arrival time of 9:00am.

Time bands are in 15-minute increments, with red areas being those where schools are accessible within a 15-minute journey (the centres of the red dots therefore also represent the positions of the schools).

Purple areas are those where journey time is between 1.75 and 2 hours, and the colours in between run in the order you see bottom right of the map. White areas (much of which are mountainous and sparsely-populated) are outside the two-hour transit time.

But there’s more – data for GIS

Plotting all the schools on a single map required quite a bit of modification to Mapumental, but there was another important part of the project that also had to be worked on, if the output was to meet all the needs of the Welsh Government.

They needed to be able to export the raw transit time data to their own GIS tools – the tools that they use to feed into official statistics. This allows the transit time data to be  combined with other datasets, such as population density, for in-depth analysis.

We added a feature which allows Mapumental to produce what is known as a ‘raster grid’ output – basically, an enormous matrix that gives every pixel on the map a travel time value. To do this, we used the open source GRASS format.

What’s next?

Bill Oates is keen to see where this project can go:

“I’m really excited at the prospect of combining the power of Mapumental with our open data, and fully understanding how accessible Welsh public services are by public transport.”

 

To him, the benefits are clear:

“Mapumental’s approach is significantly quicker than our current methods, so this work will help save us time as well as providing a more engaging output.

 

“We hope that future work with mySociety will give us a sustainable approach to calculating the accessibility of local shops, hospitals, post offices and other services on an ongoing basis to help ensure that we’re meeting the needs of our citizens.”

 

We’re looking to build on our success, and offer this service to others – initially on request but via our API as soon as we can. We’ll keep you posted as to our progress.
You can see multiple-point mapping in action, on our Mapumental Property project – now the tool allows house-hunters to take more than one person’s commute into consideration when choosing where to live.

Who might use Mapumental?

Now that Mapumental can plot transit times from multiple points, and provide RAW data for GIS applications, we have great potential for use by anyone interested in travel and accessibility. That could be in central and local government strategy, town planning, architectural consultancy, transport provision, large enterprises looking to save on parking, or start-ups in the green transport space…to name but a few.

Could Mapumental help you with your mapping needs? If so, please do drop us a line at hello@mysociety.org.

Photo of Welsh school bus (bws ysgol) by Aqwis (CC)

1 Comment