I’m excited to present sDNA version 3 for public beta testing. sDNA 3 is based on feeback from our research partners Arup, WSP, Sustrans and Tongji University, and adds an enormous amount of new functionality both for free and paying users.
- Use Open Source GIS with QGIS Support
- Increased compatibility with network formats (ability to run link-weighted analysis without fixing split links; grade separation and elevation can now be used together)
- Link to other models: export skim matrices from sDNA or use sDNA to assign an external Origin-Destination matrix (sDNA+)
- Easier to install anywhere with offline unlocking and no administrator account required
Enhanced ease of use
- Links can be switched on and off for scenario analysis (sDNA+)
- Do your stats within sDNA, no need for external tools
- Preserve text and numeric data in sDNA Prepare (sDNA+)
- Improved interface to all functions in sDNA, more helpful error messages and it’s less of a CPU hog
- Full user manual – not just for sDNA but guiding you through the theory of spatial network analysis and how to prepare networks
- Produce maps of who uses a selected link (sDNA+)
- Easy to use cycle, vehicle, pedestrian and public transport metrics (sDNA+)
- More realistic behavioural models with hybrid and banded radius, enhanced hybrid metrics for turns (sDNA+)
- Robust multivariate learn and predict tools based on generalized cross-validation
- Geometry outputs are now fully 3d (sDNA+)
- OD Matrix Input and Skim Matrix Output (sDNA+)
Users wishing to test sDNA3 can find it in the downloads folder under experimental. Your previous serial number will work but must be deregistered from sDNA version 2 before uninstalling the old version.
The user manual is here.
Alternatively if you wish to wait, the official release of sDNA3 is scheduled for September 2016.
Crispin will be presenting the latest sDNA developments at GISRUK 2015. His abstract describes (formally for the first time) the reasoning behind our continuous space algorithm. If you would like to catch up, he will be around for all three days of the conference.
The slides for Crispin Cooper’s Sustrans seminar are available here. Crispin gave a seminar at Sustrans Cardiff on sDNA models of cycle journeys, which can predict both flows of cyclists and risk of conflicts with motor vehicles, as well as map hotspots for infrastructure improvement.
Wed 28th January 2015, 10.30am, Sustrans HQ Cardiff
Sustrans contact Lindsey.Curtis@sustrans.org.uk
Ringo Chan of ARUP global consulting engineers presented an sDNA pedestrian footfall model for Leadenhall Street, London at yesterday’s Chartered Institution of Highways & Transportation event, “Planning for Pedestrians”.
Ringo’s work makes use of Pedestrian Environment Review System (PERS) data both as a predictor of pedestrian destination attractiveness, and pedestrian route attractiveness. This is a hot area of research – if you are interested in using PERS with sDNA please get in touch with Crispin for more information (firstname.lastname@example.org).
The event was well attended and the work well received – thank you Ringo.
Chinmoy Sarkar and Chris Webster recently won the Excellence in Spatial Planning Research award (academic category), for their work using sDNA to add urban morphometric data to the UK Biobank medical database.
The Awards were presented by Trudi Elliott, Chief Executive of the RTPI, who said: “I congratulate all the winners on their outstanding achievements and also to the commended researchers. These Awards highlight the contribution of academics, teachers, learners and employers into greater understanding of the creation of high quality places.”
The UK Biobank Urban Morphometric Platform is a high resolution database of more than 750 spatial urban morphological metrics for the 500,000 Britons in the Biobank Prospective cohort. The platform is being developed as a nationwide resource for evidence-based healthy city planning and other public health interventions.
The judges felt that this was an important study because it provides a robust evidence base for future initiatives that try to support built environment interventions that could have positive public health outcomes. This is a key ambition of planning, yet the basis for decision making is often weak. This study makes a major contribution to the field.
UK Biobank Built Environment Morphometrics for Wales: https://biobank.ctsu.ox.ac.uk/crystal/docs/ard-1195_UKBBuiltEnvWales.pdf
UK Biobank Built Environment Morphometrics for UK: http://biobank.ctsu.ox.ac.uk/crystal/label.cgi?id=100115
Map of distances associated with shortest-time road travel routes to Hay-on-Wye
sDNA was behind a large part of the scenario modelling in a recent report on the ecological footprint of the Hay literature festival. Crispin Cooper (of the sDNA team) and Andrea Collins (Planning & Geography) presented the results at the festival itself.
How was sDNA used in the study? Relatively simply – we produced a map of road travel distances to Hay from all locations across the UK to feed into further analysis. Using angular analysis, we were able to proxy shortest-time rather than shortest-distance routes based on minimal data – i.e. calculating travel distances assuming people take the motorway rather than small lanes, when available. All of this is possible without the need to pay for travel time data.
The facility to output a map like this is part of the feature set of the upcoming sDNA version 2. Currently this is only available to our research partners, though we are open to forming new partnerships so do get in touch if you are interested. For those of you who already have access – you would produce a map like this by making use of the outputdestinations keyword in advanced config. If you don’t want to be overwhelmed by data, you would also need to restrict your output to a single origin using origin=511326 where (in this case) 511326 was the object id for the link where the Hay festival is situated.
What happens when we finally take a break from writing software to do some research with it? This – a novel finding on spatial network layout and community cohesion published in the International Journal of Health Geographics. Some figures are pasted below.
The key result is that Convex Hull Maximum Radius 600m (HullR600c) had a significant correlation with community cohesion (R=0.25). This worked on two study areas (a data mining and separate test data set); we controlled for deprivation and urban/rural status as well. Areas with higher HullR600c allow you to get further for the same walking distance – so we suspect this is an important aspect of walkability.
A word of warning, though: this applies to HullR600c averaged over areas rather than on individual street level. On individual streets, long straight roads will have the highest HullR600 – and these are typically through transit routes with little habitation let alone community cohesion. The reason this works at area level is that we average over network links, not road length – and we know that links correlate with interesting human activity such as homes and jobs. So these anomalies are ‘weighted out’ of the analysis.
OS ITN mapping © Crown Copyright/database right 2013. An Ordnance Survey/EDINA supplied service.
sDNA attracted the attention of Cabinet Office Minister Francis Maude on a visit to the university this week.
”It is great to see the fascinating work that Cardiff University is doing to create efficient cities that best serve their communities [...]. I’m interested in how analysis from initiatives like Cardiff University’s sDNA tool could help my officials examine how our plans will shape the local environment in the future.”
See the cabinet office press release here and the university one here.
A team of students with a project based on the sDNA software won the Winter 2013 iSolve competition. This is a scheme that allows entrepreneurial postgraduates and researchers to work with real inventions in order to determine the best route for their commercialisation. Congratulations to all involved!
More information here