A Community Approach to Mapping New Zealand

Date: 14 April 2009

The New Zealand Open GPS Project began as a sideline hobby in 2004 and went on to win the 2007 New Zealand Open Source Award for the software product category. The project offers free Global Positioning System (GPS) maps that include nearly every road and street in New Zealand (excluding the Chatham Islands). Land features such as forests and lakes, and places of interest sourced from Zenbu, have also been incorporated.

The project's creator, Graeme Williams, says the project began as a solution to the simple problem of becoming lost during business trips to unfamiliar cities. He purchased a Garmin GPS unit and replaced its American base maps with New Zealand street maps.

However, when zoomed out, the system reverted back to its base maps. New Zealand became a crudely constructed and near-useless set of polygons. Armed with a passion for mapping and a Do It Yourself attitude, Graeme decided to develop the necessary New Zealand base maps himself.

A history of collaboration

Graeme obtained detailed shape files of the New Zealand coastline from Ollivier & Co. He began filling them with a mix of topographic information sourced from NZ TopoOnline, hosted by Land Information New Zealand, and from Ollivier & Co. as prepackaged datasets. Towns and points of interest were originally compiled using GPSmapper and made searchable using Mapdekode.

Once the top third of the North Island was complete, it was time to put his maps to the test. Graeme discovered that higher resolution data for the lower zoom levels were required. Working alone, obtaining coverage of the whole of New Zealand would be an almost insurmountable challenge. Graeme sought help from friends in the industry who were able to provide much of the raw data he needed.

Supported by this group of contributors, Graeme continued to develop and test his maps, making sure they could be added to by users with differing abilities and desktop technologies. In late 2005 the maps went live and by the end of 2006 they included the much demanded autorouting (a navigational aid where the map displays directions to a selected destination). The maps were then split amongst fellow enthusiasts to edit and update.

Perfection is a circle

Road testing has remained key to the project. The maps are constantly being updated to extend their coverage and record changes to already captured features, such as roads. The process is surprisingly efficient. Online community forums allow issues or bugs with the system to be reported; regional mappers pick up these reports and make corrections to the source maps. Generally within 24-48 hours, revised versions are available to download.

The project is an excellent case study in how open source products can operate effectively. Maintained by the community making use of it, the product is user-focused, which generates interest, meaning the community develops and so again does the product.

Mapping is still carried out using the Garmin GPS platform due to its wide-usage and support of third party mapping tools.

Free is not always easy

One particularly disappointing problem Graeme has encountered has been people selling the entirely free maps on auction sites like Ebay. Little can be done about this but to lay complaints for the auction sites to follow up on.

Another problem not yet overcome is to integrate the maps with a global open source mapping application. A good example of such an application is the OpenStreetMap. At present, such integration is not possible due to conflicts between accepted licensing agreements for base data.

Take part

The Garmin compatible maps of New Zealand can be downloaded from the New Zealand Open GPS Project website. Visitors to the website will find all the user information they need, including access to the online community forums.