Curious Questions: Why do maps include streets, and even entire towns, which don’t exist?

The mysteries of mapping have intrigued Martin Fone since he was a boy — and one of the great curiosities is the existence of the 'trap street'.

My journey — I use the word advisedly — into cartophilia began with an innocuous gift: an atlas.

As a small boy, I would spend hours gazing at the shapes of the continents, memorising the names of the countries and their relative position to one another, imagining the peoples and scenery I would encounter there. Picturing myself as an intrepid adventurer, I would construct elaborate, and probably unfeasible, journeys across the globe. The atlas was my oyster.

It never troubled me to wonder why so many countries in my atlas were coloured pink or why the view and perspective of our planet was intensely Anglo-centric. Maps are used, and always have been, as a power statement.

This long-standing cartographic tradition is evident in the earliest surviving map of the world, the Imago Mundi, from the 5th century BCE found in Sippar in Iraq. It represents the world, at least as the Babylonians saw it, with their principal city right at the hub. The accompanying cuneiform inscription shows that it was a copy of an earlier map and there is no reason to think that their perspective had changed.

Later maps produced by the Greeks and Jews, amongst others, also placed their principal settlements at the heart of their representations of the world, the heavens, and their place in it.

A globe, one of my treasured possessions, gave me a macro-view of the planet. In truth, it was a pretty rudimentary affair, consisting of two ill-fitting metallic halves, the join rendering the equatorial regions barely legible. At least, though, it convinced me that the earth was round, an impression that was difficult to discern from a two-dimensional map.

The Erdapfel, literally the earth apple, holds the distinction of being the oldest extant terrestrial globe, dating from that annus mirabilis, 1492. Created by Martin Behaim, who drew on his extensive travels and discussions, it was made in two halves from laminated linen which were then joined and reinforced with wood, before being overlaid with a map painted on parchment by Georg Glockenden. It can be seen in the Germanic Museum in Nuremberg.

The Terrestrial globe of Martin Behaim, 1492, also known as the Erdapfel. The Americas are not shown.

Besides being an object of wonder a globe challenged the cartographer to consider the extent of their geographical knowledge, forcing them to enter the Rumsfeldian world of known unknowns and unknown unknowns. The catch-all ‘here be dragons’ was thought to have been introduced for the first time on the Hunt-Lennox Globe, which dates from around 1510.

I have always found the Ordnance Survey map a great source of comfort and joy. Giving a birds-eye perspective of the landscape, the contours of the land compressed into a series of concentric rings, it imposed a certain order on what might otherwise have seemed just a random hotchpotch of fields, hills and man-made features. That, in itself, is not surprising as the impetus for understanding and mapping our country came from military necessity, firstly so that the Sassenachs could better understand the Highland territories they had acquired in 1745 after the suppression of the Jacobite rebellion and, then, as relationships with the French deteriorated following the Revolution of 1789, to study the layout of our vulnerable southern coastline to determine where to position troops to repel the anticipated invasion.

The first Ordnance Survey map available for the public to buy was that of Kent. Published in 1801, it cost the sum of three guineas — around three weeks’ average wage. It was a county considered most prone to invasion, but quite why the authorities did not think that a French spy might buy a copy is anybody’s guess.

The name Ordnance Survey appeared for the first time, in 1810, on the map of the Isle of Wight and Hampshire and it took until 1870 to complete the first series of maps covering England, but, tellingly, not Scotland.

For me, part of the charm of a map is that they are a statement of the area as it was at the time that it was surveyed. I have taken to buying several editions of the same map to better observe how man has progressively encroached upon the terrain. Each version of the map has its own story to tell those of us who take the time to listen.

It is a mistake, though, to take a map as gospel. As with all human endeavours, errors creep in that, once spotted, are rectified in a subsequent edition. However, such is the time, energy, not to say expense, involved in surveying an area to the standard required to produce a commercial map that cartographers are keen to protect their investment from the depredations of those who would violate copyright. One of the ways that they do that is by introducing small, almost imperceptible, errors into their maps, designed to trap the unwary and make it easier to prove a copyright infringement. These are known as trap streets.

They may indeed be fictitious streets. A BBC documentary, Map Man from 2005, claimed that that invaluable guide to the layout of our capital before the arrival of digital assistance, the London A to Z, featured around a hundred such trap streets. Perhaps the most well-known was Moat Lane in Finchley, a street off Clandon Gardens and running parallel to the North Circular, even making its way on to Google Maps. If you flipped over to the satellite view on the app, you would see that Clandon Gardens was a cul-de-sac and the putative lane just trees and housing.

TeleAtlas Directory, upon which Google Maps was based, may have fallen into the elephant trap of Moat Lane (now since removed) but they too created their own protections against copyright infringement. On the ground your search for Kerbela Street in Shrewsbury — allegedly off Meadow Farm Road, but in reality the forecourt of the Shropshire Learners and Driving Instructor Training Centre — or Oxygen Street — a small alley in the Nether Craigour district of Edinburgh — will end in disappointment.

They are trap streets as was, albeit on a larger scale, the town of Argleton, close to the West Lancashire village of Aughton, which appeared on Google Maps for several years before quietly disappearing. No explanation was ever given.

Unsurprisingly, Ordnance Survey also sought to protect their copyright by using trap streets as a sort of pictorial fingerprint, often by changing the spacing between a group of symbols, such as trees denoting a wood, making subtle alterations to the width of roads, changing the minor digits in co-ordinates and inserting other stylistic variations which did not invalidate the overall integrity of their maps.

It was through the use of these deliberate errata that they were able to demonstrate, in 2001, that the Automobile Association (AA) had violated their copyright on some of the 500 atlases, town plans and fold-out maps they had published and sold on to other third parties. By the time the case had navigated its way through the courts, the AA had agreed to pay £20 million in damages.

There is more to a map than meets the eye.