A question: Downloading a possibly ridiculous amount of data from OSM?


I’m entirely new to mapping and just about anything related to it. I recently realized that I have a need for a highly detailed, large (as in expansive) map of the road and roads connected to a route that I travel frequently. The route covers Pennsylvania and Ohio, and the area that I would like a detailed map of would amount to about a quarter of PA and about the same for Ohio, so what I’m really talking about is a detailed map with the area of about the size of half of a large state. I would like to zoom down to the nearest level where I could see individual streets and names.

The problem is that I would need this map off-line and I would need to download it. I plan on using it on a laptop in a car.

I want to integrate this map with a gps location program (I’ve found a couple promising ones).

Since I’m new to this. ( I just played around a little yesterday with OSM for the first time.) I wonder if this a completely ridiculous idea which couldn’t, or shouldn’t be done?
Maybe the file would be massive?

It seems to me that since my gps has a map of the entire U.S. and Canada stored on some sort of ram plus the operating system, surely a laptop with a decent hard-drive wouldn’t have a problem doing this.

I think my main question is this: Would I be able to download a map of this size from the O.S.M. server? Would this put a huge strain on it if I was able? Maybe people who are knowledgeable about this would know that this a completely ridiculous question. My apologies if it is.

I also should state that I don’t even have any knowledge of how I would download and use this amount of data at this time.

Thank you for any replies.
I really appreciate it,

I’m not enrirely sure what options would fit your needs best, but in general a phone/tablet with Android and GPS would show a lot of details after installing for example OsmAnd and downloading data for desired areas in it:


Thank you for the suggestion. It may be that I just don’t know enough to even say what I need yet. I do know that I’m shooting for a large screen so I’ve been looking at laptop based programs. I keep getting drawn into android programs with an emulator but they all seem to smartphone sized displays no matter what they’re run on. On the Linux forum a person suggested QGIS which seems to be closest to what I think that I want. That is what led me here wondering if It would be possible to download a file the size of a whole state map with several layers of resolution.

Just for clarification, I’m looking for a display with many miles of map resolution, not a small area blown up for better visibility on a large screen.

I guess that my question might be this - would it be hard on the osm server to download a whole state map with several layers of (zoom, magnification, higher resolution) where I could start out at just seeing major highways and then zoom level where I could even see alleys when needed while anywhere in the state?

Sorry for such ambiguous questions, Hope that I’m not wasting time with these.

Thank you again,

Maybe if you tell us why you want a map on your laptop and what you want to do with it, we can help you better.
All programs including your gps are working with data and make a map from that data.

Yes, downloading map images for such a large area would be hard on the OSM server.

Therefore, offline maps generally use map data which is turned into map images locally on your device. This is how the popular apps for using OSM offline (such as OsmAnd) work.

I’m not sure how exactly this works with QGIS. As far as I know, it usually downloads map images for its OSM layer. It also has capabilities for locally turning data into images, but I’m not sure how these work with large amounts of OSM data. In any case, be prepared that it may be harder to use than the Android offerings, as QGIS is used a lot by professional GIS people.

You could try a shapefile on Qgis downloaded from https://extract.bbbike.org/ .
There are many other formats and you can stretch a polygon over the area you want to download.

You could also download the free Garmin Basecamp https://www.garmin.com/en-AU/software/basecamp/ and then download one of the many free varieties of Garmin suitable extracts from Bbbike and view those using Basecamp.

You didn’t mention what OS your laptop is running so it is difficult to give a concrete recommendation. QGis etc would seem to be a rather exotic way to solve the problem, you should give https://wiki.openstreetmap.org/wiki/Software/Desktop a look for a far too long list of possible solutions

https://wiki.openstreetmap.org/wiki/Cruiser uses mapsforge format offline data so would be a realistic candidate, an alternative approach would be to use vector tiles, and render them locally, but likely somewhat more involved.

Check https://www.openandromaps.org/en/downloads/usa_en. You can download map databases in several formats.
I use them with OruxMaps (free version) and it does the job.