Highlight unusually low headways in chart

[devinmatte]

Motivation

Show headways which are 50% under the benchmark, often meaning that there's bunching

relates to #969

Changes

Testing Instructions

[devinmatte]

I'm not married to blue as the color, I just didn't want to use a color we already use on the legend

[idreyn]

I think we should consider repurposing yellow for bunched trips. Then we could do something like this:

[devinmatte]

You thinking we shouldn't differentiate 25% late vs 50% late with different colors like we do today and instead just do red for all late trips?

[idreyn]

Well, I think the system that we have works well, but if we're introducing a color for bunched trips, I think it should be a "warning" color like orange or yellow. My first thought was that we'd no longer be able to use it for slightly late trips, but maybe we could keep it for both?

[idreyn]

You thinking we shouldn't differentiate 25% late vs 50% late with different colors like we do today and instead just do red for all late trips?

So basically yes, that's the proposal. But I don't feel very strongly about it.

[devinmatte]

Perhaps we can call out early trips (25%-) and bunched trips (50%-) with the same colors as 25%+ and 50%+?

[idreyn]

yes I think that makes the most sense!

[devinmatte]

How about this @idreyn?