Why are labels duplicated?

Map Tiling

The interactive mapping tool used on this site uses a system of map tiles to provide smooth interaction. An on screen map is made up of several tiles, each 256 pixels square, and each one is created independently, complete with labels. The labeling algorithm works on one tile at a time, without any knowledge of the labels placed on adjacent tiles. Consequently a long road running through multiple tiles may be labeled on every tile.

Map Printing

Tiling is only used for the interactive maps. When you create a printable PDF map, the entire map is redrawn as a single image which allows much smarter label placement. You will find PDF maps have fewer inappropriate label duplications.


Home News Help Apply For Access Create Maps Links About Contact Us Email: Password: create account reset password	Back to help Why are labels duplicated? Map Tiling The interactive mapping tool used on this site uses a system of map tiles to provide smooth interaction. An on screen map is made up of several tiles, each 256 pixels square, and each one is created independently, complete with labels. The labeling algorithm works on one tile at a time, without any knowledge of the labels placed on adjacent tiles. Consequently a long road running through multiple tiles may be labeled on every tile. Map Printing Tiling is only used for the interactive maps. When you create a printable PDF map, the entire map is redrawn as a single image which allows much smarter label placement. You will find PDF maps have fewer inappropriate label duplications.