How to move offline map data to another drive

Open Settings in Route by Zaweba and choose a different folder for map regions, on whichever drive you want them kept. The one rule is that the folder must be outside the app's own folder. New regions are then prepared there, and Map > Open the regions folder always shows you the current location.

Offline maps are the reason Route works without a signal, and they are also the part of the app that uses the most space. Moving them is a sensible thing to do on a PC with a small system drive and a larger second one.

Why maps take room

A small county is a few megabytes to download, but a whole country is far bigger. Great Britain is about 2 GB to download, and preparing it builds an address index, a routing graph and map tiles on top of that. Coastal regions also fetch OpenStreetMap water outlines once, about 0.9 GB. Keep a couple of large regions and your system drive will notice.

By default the regions live in your user account's local app data, which is usually on the same drive as Windows.

Making the move

First, check what you already have. Map > Open the regions folder opens the current location in File Explorer. Each region keeps its data in its own folder, so you can see at a glance which regions you have and how large each one is.

Next, decide where the maps should go. Make a plain folder on the roomier drive, with a name you will recognise, such as Route maps. Do not put it inside the folder Route is installed in. Keeping maps apart from the program means updating or reinstalling the app never touches your prepared regions.

Then open Settings and choose that folder as the place to keep map regions. Use Map > Open the regions folder again to confirm Route is now pointing at the new location.

What about regions you have already prepared

Choosing a new folder tells Route where to look and where to prepare. The regions in the old location are not part of that choice, so decide what to do with them.

If a region is small, the simplest course is to prepare it again in the new place from Map > Choose a region. A county prepares in seconds to minutes. Once it is ready, you can delete the old copy, either from the region chooser before you switch folders or by hand from the old folder with Route closed.

For a large region, consider timing. Preparing Great Britain again means the download and roughly 8 GB of free memory, so do it when the PC is free. The command line can help: ZawebaRoute.exe --prepare with a Geofabrik id or an .osm.pbf file prepares a region without opening a window, and can write a log. If you already have the extract as an .osm.pbf file, Use a map file I already have prepares from it without downloading again.

Getting it right

Pick a drive that is always there. A fixed internal drive is ideal. An external drive works only while it is plugged in, and if it is missing Route cannot reach the maps on it.

Leave room to grow. Preparation needs space for the pieces it builds, not just the finished map, so a drive with only a little more space than the download is not enough.

Remember that saved routes are separate. An .ozroute file keeps your stops, time windows, options, set-off time and via points, not the map itself, so moving map regions does not disturb any route you have saved. Once the region is ready in its new home, open your routes as normal.

If something looks wrong afterwards

If a route will not calculate after the move, check that the region you are using appears as ready in the region chooser. If the engine seems stuck, Map > Restart the router restarts it without affecting your stops or saved routes.

A few minutes in Settings is all it takes to give Route by Zaweba's maps the space they need.