Riding every street in Cambridge

I have started cycling along every street in Cambridge. Here’s why.

Street mapping in progress.
Image as described adjacent

Often for this newsletter we would like to print a map. Indeed we sometimes do, but it always has to be a sketch map based on local knowledge because to reproduce a map in print is nearly always infringing someone’s copyright (typically Ordnance Survey) and the fees are utterly prohibitive for this modest publication. But now there’s a solution in prospect, and it dovetails perfectly with cycling.

OpenStreetMap is a collaborative project which aims to map everywhere. Unlike some projects, it does not have an American focus: it was started here in the UK and has lots of European contributors. There is less incentive to do this in the USA because Government maps there are freely reproducible.

GPS is the Global Positioning System. Three dozen or so satellites in earth orbit transmit information to anyone who can receive it; there should always be three or four in view from anywhere. This information is used by the receiver to provide its position accurate to a few metres. The receiver collects the route you travel (and can also calculate from successive positions your speed, how far you’ve travelled, and lots of other odometer-type information). Your track can be later transferred to a computer.

The mapping is made possible by the ubiquitous Internet, the enthusiasm of a core team of people, and the availability of cheap, highly portable GPS receivers (see box). Mine is a Garmin Geko 301, about the size of a mobile phone, and cost about £120.

The idea is that people gather track information for their area along with details of street names, amenities, road types and numbers and so on, annotate the tracks with this information, and merge it with the information others have created. This is then transferred to a large database on the Internet which stores everyone’s mapping. Some features, such as rivers and land use information can also be traced from copyright-free satellite imagery or possibly scans of post-war OS map now out of copyright, using computer tools available from the project.

A bike is an ideal tool for collecting information for urban areas. A car is too fiddly: if you map housing estates, as you must, then there are an unbelievable number of dead ends. A car is, of course, highly environmentally damaging used like this. The GPS receiver can be mounted on the bike handlebars and works better than in the closed confines of a car.

From my point of view it brings together lots of passions and skills. Cycling, obviously. But I’ve also been fascinated with maps since childhood. Not having a long cycle journey to work any more, it provides a motive to get some exercise. Two or three of hours can cover an area like Barnwell, say. This may not seem large, but if you cover every street it works out at 40km or so with constant starting and stopping, so good aerobics. It also involves computers and graphics, key skills and interests of mine. And for those that relish it, there is the gadgetry.

An OpenStreetMap of part of eastern Cambridge, largely from data I contributed to the project during October. (Copyright © 2006, OpenStreetMap.org. This work is licensed under a Creative Commons Attribution-ShareAlike 2.0 License.)
Image as described adjacent

Some bits of Cambridge had been done when I got involved in September, but only in an ad-hoc way: most of the main streets, only a few side streets, and even fewer with names. However, in the past few weeks I’ve been able to complete a large chunk of the east of Cambridge: all of Cherry Hinton, Fulbourn, Teversham, Barnwell and Ditton Fields, Abbey, Fen Ditton, north Romsey and Petersfield and the Historic City Centre. Great Shelford village and Stapleford are also complete; next in line for me is Chesterton. I’m avoiding the Cherry Hinton Road corridor as someone else is promising to work on that.

There’s a lot more to do though. If anyone is interested in joining in, it’s an open house. I’d be happy to show anyone how to get started. A group of enthusiasts had a mapping party in Rutland recently. They mapped the whole county in a weekend. Maybe South Cambridgeshire villages could receive the same attention.

Having lived here for more than twenty years, and having biked all over our city for cycle campaigning, I thought I knew it very well. But I’ve discovered lots of streets, parks, churches, post offices, even cycle ways, that I didn’t know existed, some only a few hundred metres from home.

Maybe one day not too far away, we can use maps we have generated ourselves for the Cycling Campaign’s online route planning system and for the paper cycling map as well as the basis for more maps in this newsletter.

David Earl