Check out stellarium - for education, I think it is perfect. Both free and Free, cross platform, relatively easy to use.
Educationally, I think providing a full package like stellarium is better than a static, short list that you propose simply because it allows exploration, satisfying a question, etc.
Give us a shot at UnwiredLabs and LocationIQ. We've got geolocation, geocoding and Maps APIs.
For cellular + WiFi geolocation, we've got our own proprietary datasets
For geocoding, we use a bunch of open-source datasets
For maps, we use OSM tiles
P.S If it wasn't obvious, I work at unwiredlabs/ locationIQ. ¯_(ツ)_/¯
This sounds like a case for using GRASS GIS with QGIS as a front end with possibly a plugin or two. (Note that you can probably get more help over at https://gis.stackexchange.com/).
GRASS GIS, commonly referred to as GRASS (Geographic Resources
Analysis Support System), is a free and open source Geographic
Information System (GIS) ...
Google Maps allows you to do this by setting road types you would rather avoid or by using "alternate route" methods.
To change a driving route, click and hold a spot on the route and drag it to a new spot on the map. If you're using Maps in Lite mode, you won't be able to drag to change routes.
Basically you let it plot your route then just drag around ...
I'd recommend taking a second look at the TomTom APIs. There should be extensive traffic history for most locations to cover your needs. This question should also partially address your concern, or at least prove that the info is available.
There's a lot out there, so I'll list a few I know or have used personally.
Full map stack services:
Mapbox: Excellent hosted tiles, geocoding, routing, more. Uses open data as well as proprietary data. This can improve the quality of their results but also comes with usage limitations. Predictable pay-as-you-go pricing but can get expensive at higher ...
I would recommend giving a try to TomTom Routing API.
The API is quite easy to understand. You can do 2.5k routing request per day for free.
And API Explorer: https://developer.tomtom.com/content/routing-api-explorer
I'm not quite sure about an app that allows you to specify your speed on different road types but from former experience using The Field Trip app (by Google) where it looks for sites of interest around you,allows you to mention certain road types(i'm not sure i just heard it from someone).
it's not much of an answer but i'll find out more and inform you when ...
There is also another freebie Celestia. The description reads: "Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects."