show which side of the street has bike lanes

[pdurbin]

As discussed in the 2025-06-02 BCU Labs monthly meeting, the map would be much more helpful if it showed which side of the street the bike lane is on. This makes a night-and-day difference when the lane is only on one side!

Even Google Maps doesn't do this but https://www.opencyclemap.org does. I'll use St. Paul in Brookline (discussed last night) as an example.

On the stress map, there's a single color for the road. You have to drill into it to know if there are bike lanes (and on which side of the road they are)

The OSM data

From https://www.openstreetmap.org/way/8648038#map=17/42.348320/-71.116299&layers=C

OpenCycleMap shows which side the bike lane is on (north-bound)

OpenCycleMap key

Related:

• cycle lanes and shared lanes are too similar (blue dashes) cyclosm/cyclosm-cartocss-style#700

[sckilcoyne]

I think that this may be achievable by using the line-offset parameter when defining the line styles. I have not tested using this feature at all, so I don't know how good or bad it will look when you try to offset the line in both directions.

[sckilcoyne]

For what I would expect this feature to look like when implemented:

• Keep the current behavior of showing the worst LTS rating of the street at low zooms. There is still some refinement needed on how we display data through the different zoom levels, but when looking at city-level zooms, keeping a simplified view for clarity on city-scale network should be the goal.
• At a reasonable zoom level, the line would split into a line for each direction. Exactly where this breakpoint is we'd have to experiment with.
• Only separate lines if they are different based on direction. Most streets have symmetric ratings and the map will likely be less crowded by only showing each direction if they are different ratings.
• When separating lines, include directional arrows. Show one way biking streets on the map #23 should be completed as a prerequisite.
• As we get working on this, we will need to make a decision on how we want to display direction versus location. By this I mean: some oneway streets have a bike lane in the direction of travel on the left side, others have a bidirectional bike lane on one side, basically direction and side of street aren't consistent. My initial preference is to ignore location and always show based on the center line of the street and standard travel direction sides. This project is about the network and now fine grained navigation, and getting too deep on displaying "true" to the layout will just lead to more confusion/complexity than is required for this project.