Alasdair is currently Professor of Urban Studies and Planning at the University of Sheffield
What’s your background using QGIS?
I've been using QGIS for about 7 years. It forms a key part of my toolset for my research in the fields of urban studies and planning at the University of Sheffield, as well as during consulting work helping businesses enhance their geospatial analysis capabilities.
What are the benefits of QGIS for you personally?
For me, the benefits of QGIS are probably too many to list but some of the top ones are as follows:
- It's free and open source
- Because of this there is constant innovation and development and the rate at which it’s constantly getting better and advancing is amazing
- The quality of cartographic outputs users are able to produce
- Efficiency in workflows - I have to click less using QGIS than in other tools I've used – as a trivial example, the drag-and-drop functionality between colour patches in Symbology
- Plugins! Like the TravelTime plugin of course, but so many more too
- User community - I have learned so much from so many
- Base map integration via XYZ Tiles
- More fundamentally I enjoy using it and it has inspired me to keep learning and developing my skills
What was the inspiration behind your recent tweet that got people talking?
I actually did the analysis last year when comparing commutable areas in San Francisco vs London using public transport. I wanted to use isochrones for this because I think they present space in a way that makes sense. Distance is important, but when we’re talking about commuting it’s clear that time is of much greater value.
To run the analysis I used the TravelTime plugin in QGIS to create isochrones showing the area within a 90 minute commute into the city centre by public transport, during the morning rush hour. It’s a very simple example of the power of visuals to tell stories.
Alasdair's original analysis
What has the reaction been?
You never really know what things will particularly grab people’s attention, but this certainly did! There’s been plenty of discussion in the comments and beyond around how and why the two cities differ so much, as well as suggestions for other cities that people are interested in seeing the same sort of analysis for.
It was particularly interesting to see people’s intuitive reaction to isochrones. In some cases we may think that an area is ‘reachable’ because there is a train/bus/ferry that can get there within the 90 minute time limit, but these services don’t run every minute of the day and so if you want to arrive at your office at 9am, not all of these routes will actually be feasible in reality. On top of this there is of course the need to walk from your house to the public transport stop and again to your office at the other end, and people often forget to include this walking time when forming an initial ‘gut feel’ around whether an area is within reach or not. The great thing about the TravelTime tool is that you have the freedom to tweak the parameters however you want – and the end result will be meaningful and useful.
How did you first find out about the TravelTime plugin?
I think I saw it on Twitter first, shortly after it came out last year.
Had you used any similar plugins before?
Yes, I’ve used a variety of other isochrone tools before, in a range of different GIS packages.
How does the TravelTime plugin differ to those you’ve used previously?
The TravelTime plugin is noticeably different in a couple of ways:
- The results appear to be more granular, producing isochrones that are detailed even at a very local level
- The results seem more accurate when I check them manually, either against what I know from personal experience, or against other online tools for specific point-to-point journeys (e.g. using Google Maps)
How easy or difficult was the TravelTime plugin to use?
To be honest, I found everything about the plugin easy, it really is a great tool. Anything that isn’t immediately obvious is easy to pick up with the help of the video tutorials and documentation. It's particularly helpful to have a basic ‘point and click’ option for each of the tools, as well as more customisable ones where you can play with the more fundamental parameters being used. The support page on the website – and the tutorial videos – are really useful too.
What features would you like to add if you could?
Just keep adding more countries!
To start doing your own isochrone analysis in QGIS, you can find the TravelTime plugin by searching for ‘travel’ in the QGIS plugins window:
To get hold of a free API key, please visit here.
Create travel time polygons and matrices with the TravelTime API