Hi Stuart - I'd recommend bookmarking your location to make it easier to retrieve (see my post below from 24 January 2015).
My location is shown about 20 miles wrong.
You'll need to be signed in to save bookmarked locations. Then press the bookmark icon next to the search box at the top of the route planner map, click Add, type in a name for the location and click SAVE.
i could not save my desired location
Hi Richard - The best thing to do is bookmark the location you want. To do this drag and zoom the map so that it is centered on the correct location and press the bookmark icon (to the left of the search box at the top of the screen) to bring up the bookmark list where you can then save it. You can then go straight to this location from your personal home page but selecting it from your My Places panel or you can select it from the bookmark list in the route planner.
My location is shown as about four miles wrong. It always shows the same place( middle of a field!) and no indication of where I am really am. Can I correct it permanently?