Validation zhuzh-up: PT speed computation

[KasiaKoz]

Resolves: #145 - Add speed computation and checks

• Adds a method to get a DataFrame with routes : speed (where the speeds are between stop pairs: crowfly distance times a network factor that defaults to 1.3)
• Adds a method to get average speed for each route (average between stop-to-stop pairs)
• Adds checks for 0 and infinity values of speeds in the validation report
• Adds a geojson/shp file output with stop-to-stop speeds in standard outputs, example pic below:
  

Nb. Part of a wider validation upgrade series. I'm leaving updating the notebook: 6.1. Validating Network: MATSim Specific to last in the series.

[elizabethc-arup]

This is a really quick and effective way to visualise and validate the speeds of the schedule :D I had a few questions in regards to the network factor:

• Why is it used instead of the actual length of the route / links?
• Would the idea be to adjust the network factor based on how windy the roads are in an area?

[KasiaKoz]

Why is it used instead of the actual length of the route / links?

The schedule object doesnt have any information about the network links it's referring to, but mostly laziness. This is a very valid point and I updated the PR with extra functionality. If you pass the network links geodataframe, the method will calculate the routed, network distance and use it for a routed speed. it will return both speeds, because I think each has its' benefits to be looked and limitations.
It's baked into standard outputs to do this automatically and output both speeds as geojsons (/shp files if requested)

Example routes speed geojson (highlights a bad speed for a bus due to a bad snap)

Would the idea be to adjust the network factor based on how windy the roads are in an area?

Yeah I guess different locations will have a different target for a network route to straight line distance ratio, so I left it open to give the user flexibility :)

[elizabethc-arup]

This looks really good! I especially like the idea of having both the options of using the network factor and the route distance to calculate speed which could also be handy for quick visual validations. :D