Add busways

[claysmalley]

Fixes #308.

Since it looks like purple is going to be the color for public transit, infrastructure dedicated to public transit might as well be purple too. This may influence design decisions about railways dedicated to public transport (subway, funicular, etc.) as #476 progresses.

[claysmalley]

After some discussion on Slack, I think busways may need lowlighting instead of highlighting. Dull gray works pretty well, and helps indicate that these serve a special purpose but are not accessible for general traffic.

Bonus screenshots with railroads from #476:

[ZeLonewolf]

At high zoom, the busway is gray cased in black. Is it our intent that non-drivable roads like this have a common fill color? Just trying to think through if there's other feature classes that fit the mold here.

[claysmalley]

Pedestrian streets come to mind: #185

[ZeLonewolf]

Exploring a subtle purple at z15+. What do we think?

[1ec5]

Do any busways run near county lines? The faint purple might be too similar to the border highlight for admin_level=6.

[claysmalley]

Here's a busway in the Philadelphia suburbs that runs close to a county line: (localhost link)

[ZeLonewolf]

That's a weird example because the road sits on top of the county line, but this is what it looks like zoomed way in:

[ZeLonewolf]

Another example, localhost link

[ZeLonewolf]

Relaying @claysmalley comments in #476:

If busways are rendered in purple in #477, it may set a precedent for public transit railways (subway, tram, funicular, etc.) to be purple as well.

I agree that what we're searching for here is the general case for how we want that collection of features to render.

[claysmalley]

I'm considering a more lavender hue to distinguish from taxiways better. I'm still indecisive on whether busways should be highlighted with a particular color on the default map, or lowlighted with a dull gray.

Amsterdam Schiphol Airport:

Almere, Netherlands:

[1ec5]

The “highlighting” in #477 (comment) reminds me of how city street maps highlight road routes in highlighter/pastel colors while keeping the width realistic. This will be an important tool at high zoom levels once we implement realistic road widths (#372 #486), so I’m a bit hesitant about introducing road fill colors for other purposes such as distinguishing modes of transportation. What if we go back to the grayed-out fill but change the casing color?

[ZeLonewolf]

Thinking about this more, should we treat a busway like a no-access service road?

[ZeLonewolf]

Would it make sense to come up with a design scheme for roads tagged access=private and similar, and then unify that with busways?

[claysmalley]

I think so. Colorful busways may be appropriate for a future enhancement that enables switchable layers (#25), where we may want to highlight busways on a public transit map. But we're building the default general-purpose map first, and busways should probably have a similar treatment to other private-access roads.

[ZeLonewolf]

Could this be as simple as "whatever service roads are tagged, but purple instead of black casing"?

[ZeLonewolf]

Also note that a legend entry is now needed.

[claysmalley]

I don't think it's clear enough from casing color alone that this is not a legally driveable road. We'll need to decide how to display private-access roads before we can fit busways into the picture.

[1ec5]

I agree that what we're searching for here is the general case for how we want that collection of features to render.

Frankly, I don’t think it’s necessary to make all public transportation infrastructure the same color, as if all public transportation is a thematic overlay apart from the basemap. Public transportation is such a diverse range of features. Two users may not even agree whether air or rail transportation counts as public transportation, based on what’s available in their respective areas, so I don’t think we can count on them to intuit the relationship based on a color alone.

I don't think it's clear enough from casing color alone that this is not a legally driveable road. We'll need to decide how to display private-access roads before we can fit busways into the picture.

I think it should be the other way around: we’re already showing plenty of restricted-access roads undifferentiated from public-access roads, so adding a few that happen to be busways doesn’t exacerbate the problem very much.

Let’s figure out a general restricted-access treatment separately in #679. In the meantime, a busway shares more in common with a public-access service road than it does with vacant land, which is how we’re depicting busways currently. If we’re concerned about confusion with drivable roads, we could have the label simply say “Busway” instead of the road name, though many will already have “Busway” in the name.

[claysmalley]

Bringing back colorful busways, this time in a desaturated mauve to match the public transit icons added in #845.

[claysmalley]

Guided busways are included now, styled identically.

[ZeLonewolf]

I think this is good enough to add to the map at this point.

We could probably argue about the exact width and level of prominence but scrolling around, it doesn't seem like it's overpowering, nor does it crowd out other features.