Back in December I blogged about Project Drake, to map the University of Cambridge. Surveying for this has proceeded steadily over the last eight months (April was somewhat wet, as you know, but apart from that all went pretty smoothly). With the recent upload of data for Trinity Hall, Trinity College and their outliers, it is now essentially complete: 31 colleges, ~10 campus-like sites, several thousand buildings.

The Colleges, which are all independent of the University, and Addenbrooke’s Hospital where several University departments are based and more properly now known as the Cambridge Biomedical Campus, have all kindly co-operated in allowing access for surveying, and the University has provided most of the survey data to OSM so it is both a provider and consumer of data. The software will be released under GPL shortly.

I am currently putting the finishing touches to a custom rendering (which goes down to zoom 19, about 1:1,500 on a typical monitor with 45m map tiles, but just for the University area, about 8 square kilometres) using its existing map style as a starting point. These are provided via a slippy map, an API (JSON) and iframe embedding for third-party sites, a dynamic search index, and artwork for a paper map (at 1:7,500). The website isn’t publicly available yet, but we have http://map.cam.ac.uk reserved for it. We hope there will be a “productisation” phase next (the current exercise is formally a “feasability study”).

As well as all the University and College buildings, though you can’t see it on the Mapnik rendering, we also have (E&OE) all the cycle parking, disabled parking, building entrances and site entrances. The quality of the data before I started varied considerably from college to college and site to site, varying from nothing at all for the Silver Street/Mill Lane site to a beautifully mapped Wychfield (part of Trinity Hall). However, even for the previously best mapped areas, I’ve improved lawns, gardens and paths, added entrances and generally made everything more consistent and rectilinear.

In particular, there is a comprehensive building and site reference ID scheme (based on the University Estates Department’s internal numbering). This allows us to link up the index with with the geographical data from OSM, including at the level of entrances.

On the whole, the tagging scheme I set up at the beginning has proved robust. There are some difficult edge cases, particularly where walkways penetrate buildings (there are many collonades and the like, and some “streets in the sky” and a few subterranean buildings, roof gardens etc).