The art of cartography mapped out

Next to cash and a passport, a map is probably the most important thing a traveller can carry. Without one, you might not be able to determine your destination and if you did, you certainly wouldn't know where to go once you got there.

If you're lost, Jack Joyce is the guy you want to be with. He runs Vancouver's International Travel Maps and Books-the largest store of its kind in North America. He's also the president of ITMB Publishing, one of the largest map publishers in the world.

Joyce started publishing maps when he became frustrated trying to find maps of South American countries. "No publisher made maps of any single countries in South America back in 1980," he says. "Until we did them, they didn't exist.

"The way maps are made is changing," Joyce says. "Traditionally, they were scribed on sheets of plastic, and you etched out the part you want to keep," to form the printed image. "That ended in the 1990s when both PC and Mac computers could be used."

The art of making maps is called cartography, and historians estimate people have been drawing maps for at least 7,000 years. Today, the modern cartographer gathers data from many sources, sifts through it, and creates an extremely accurate map using illustration software.

There are two ways to create a new map. The easy way is to modify and license a map that has already been made. For example, a Canadian publisher might license a map of Moscow from a Russian publisher, translate it, and market it.

The second way-starting from scratch-is more interesting. I envision someone wandering around with a sketch pad, but Joyce tells me there is much more to it than that.

First a cartographer is hired. He or she often lives in or near the area to be mapped. Cartographers are not only experts in geography and design, they must be good researchers. They collect all the base information such as aeronautic and topographic maps, and information from government agencies. Geographic Information System data is used to organize and manage spatial information based on the physical features of the land, confirming the location of things like mountains.

The cartographer uses this material to draw the artwork on a computer. It's then sent to the publisher's cartographic editor, who notes errors. A copy of the map is plotted out and sent back to the cartographer for revision. Because the cartographer works on small areas, this is usually the first time anyone sees the map as a whole.

At this point, new information is added from travellers, tourist offices, and guidebooks, such as the location of a new museum. Joyce explains the symbiotic relationship: publishers will use information from maps in their guidebooks, and mapmakers will use information from the books on their maps.

The map is then checked for accuracy through "ground truthing", which means going out to directly observe areas that are mapped, to make sure that they are correct. This involves driving around an area to see if the major features are correct or if there are changes, like a new motorway or bridge.

Once everyone is satisfied that the map is accurate, it goes off to the printer and is distributed to retailers. The whole process can take several years.