What gets updated?
The Ordnance Survey is continually surveying Great Britain and updating their mapping.
The maps are split into tiles which range in size from 20km by 20km for the 1:250,000 scale OS Road Map to 5km by 5km for the 1:10,000 scale OS Vector Map Local.
Every three months or so, we get a digital delivery of map tiles that have changed since the last update.
These updates vary in size but are typically 10-15% of the total tiles in a map set are re-delivered to us on each update. Over the course of a year, four updates can add up to a lot of changed mapping.
What that signifies is that a change was made on a map tile, however what it does not tell us without much closer inspection is if the change was simply a spelling correction, or a new bridg