In today’s instalment of our ongoing interview series, we chat with Gregory Marler, the man who almost single-handedly mapped Durham, England in OpenStreetMap.


1. Who are you and what do you do? What got you into OpenStreetMap?

I put Durham on the map, but more of that later. During the day I’m a geospatial consultant but still “get my hands dirty” doing web development work. The OpenStreetMap way to answer who I am is to see my “how did you contribute to OSM” profile where I’m described as a “heavy mapper”. I’ve hacked together various projects and prototypes using OpenStreetMap data and all manner of subjects including toilets, elephants, cycle parking, and places to donate food.

Back when PDAs were high-tech I was young and wanted more reasons to justify buying a £30 bluetooth GPS dongle. Getting involved in OpenStreetMap from the homepage was daunting, and so I spent time geocaching. In 2006, OpenStreetMap got mentioned at work and my boss had been friends with founder Steve Coast, so said I should meet him. I went to a mapping party in Southampton, which included stumbling across the Ordnance Survey’s HQ and taking a cheeky photo (they had the opposite of an open-data attitude then). Sadly, I don’t know what happened to that photo. I didn’t contribute a lot to the Southampton map, but just meeting other mappers gave me confidence to work out the tools. It was fun to get outside and explore, and I met people with such varied styles/personalities in mapping.

2a. Tell us about your “Living with Dragons” project. 

I left my full-time job to go to university in Durham, which is a small city really far North from the London. I looked at OpenStreetMap and the city just had the A1 motorway and the River Wear running through it, if it was an old-style map then they might have drawn a picture and labelled “here be dragons” for this unknown place far from home. I’d probably contribute to OSM while I’m here, so can I do it without looking at any other maps? On my first night I setup the Living With Dragons blog( and declared the rules to be that I could only look at maps if the copyright license allows me to reuse/republish and modify the map. Someone once sketched me out a map to their house (implied permission) after I explained I couldn’t “just Google it”.

As a developer, I had always seen the potential of OpenStreetMap and keep dreaming of a million ways to use the geodata. However my blog focused on exploring Durham, the occasional university escapade (where maps or locations were involved!), and the lighter side of being part of the mapping community rather than heavy programming tutorials. A lot of my Computer Science degree was spent in “the dungeon” computer room, so getting outside to map was brilliant. I even added an extra year to my degree that took me to Vancouver, another country for me to help map on the ground.

2b. How has it gone? Is Durham now fully mapped?

Ed, you’ve asked me before if Durham is mapped or when it will OpenStreetMap be complete. The great thing about the project is no. Even when I had barely started, others saw I had mapped everything and still found more to map. I’ve just written about one such incident where bins were added to the database. The world also changes and that’s driven me to [map new housing estates](( with loads of examples mentioned on Living With Dragons. The amazing thing is that OpenStreetMap is now an amazing geodatabase and non-geo companies are starting to understand that they can take hold of the data for some amazing value. My work has become less about personally choosing it as a data source to code with, and more about supporting companies and councils through consultancy on how to use the project in the best ways.

Keeping it as a personal hobby, I’ve recently been re-energised to map the house numbers and out into the Durham countryside there are footpath “stubs” where I need to get off my bicycle to survey them well.

3. What are the unique challenges and pleasures of OpenStreetMap? What aspects of the projects should the rest of the world be aware of?

There are so many things that I enjoy in OpenStreetMap: getting outside, knowing I’ve help make a brilliant map that I share with anyone who will listen, and also seeing a map in various places and being able to point out that it includes contributions from me. It’s an especially proud moment when I point to “my” roads in a news article about Humanitarian OpenStreetMap saving lives. Although I’ve only spent the odd hour of my time, it’s been added with hundreds of hours mapping per disaster.

There’s also the great pleasure of the people in OpenStreetMap. Remember I said I didn’t get involved until I had met other people? The project took off with mapping parties and people meeting in pubs, and there are relationships that still stand really strong even if they only meet at conferences every few years. The reliance on a relational community also includes unique challenges. OpenStreetMap can’t rely on pub-going British male geeks alone. Over the last two years this has finally started to be dealt with. Missing Maps groups are attracting massive crowds, less technical people that prefer Facebook over IRC, yet they are as important as everyone else and demographics cross over. The Maptime) formula seems interesting, and I’ve started to organise one in Durham. It’s not restricted to OpenStreetMap, and it doesn’t have to meet in a pub. I’m still seeing where this goes, but so far it’s been fun. Meeting in-person is a great way to learn about different projects, tricks, or clever things in OpenStreetMap. Around the world I’d advise people to attend a conference, meetup, or mapathon. If there isn’t one near enough to you then start one. It’s rather bad that a lot of the years I’ve been in Durham I’ve neglected this simple task, but I’m delighted to see we’ve got a small community starting to form right away.

4. What do you think can be done to engage mappers in places like Durham, where there are no more empty spaces on the map?

As I told you, there are no empty spaces if you look at different features to be mapped. In previous years I used to encourage people to use the map even if they didn’t contribute to it. More eyes on the map makes us more aware of the errors, out-of-date bits, or missing areas. Now I can say use the map in other ways too: build websites, take screenshots as evidence the council should add cycle parking in a neglected area, and so forth. It is by using the map in so many ways that we extend and expand the uses it can have, demonstrating reason for us to those new things.

Oh, and meet up. Have fun. Enjoy talking about the map. Even during one Durham Maptime session, we discussed an outdoor artwork representing the UK and our conversation pointed out it could/should be in OpenStreetMap. At our table we edited the OpenStreetMap to map what it was, with different people suggesting useful tags to include.

5. Last year OSM celebrated its 10th birthday, where do you think the project will be in 10 years time, both globally and in Durham specifically?

I hope there will be more cake, we missed that opportunity this year in Durham. Who knows where OpenStreetMap will go. I have little doubt it will still be around, I hope I’ll still be meeting up with people and enjoy talking about it.

Other than that, let’s wait and see how the world changes. In 10 years time OpenStreetMap might have more hover-board lanes than cycle lanes, or we might still be walking everywhere.

Many thanks Gregory, and congrats on your success in Durham. Great to learn about Maptime Durham, I hope it grows rapidly. Hopefully others will follow your lead.

You can see all the Open Geo interviews here. If you are or know of someone we should interview, please get in touch, we’re always looking to promote people doing interesting things with open geo data.