Apropos of this diary entry, I realized today that a toggle feature to control the display of the heatmap on your profile is now available.

Thanks @jweare for doing the analysis. It’s super interesting. I tweaked your script a bit and pulled the global state of slipways as of yesterday 2026-01-10. The highlights are:

nodes: 45258
  orphans: 14745
ways: 48309
  leisure = slipway node missing: 17499
  leisure = slipway node at start: 8284
  leisure = slipway node in middle: 1206
  leisure = slipway node at end: 21428
  leisure = slipway on way: 19594
  leisure = slipway is a closed way: 1265
  way combinations:
    leisure = slipway way only: 16830
    leisure = slipway node only: 28046
    leisure = slipway node and way: 2764
way tags
  highway = service (33389)
  leisure = slipway (19594)
  service = slipway (13896)
  service = driveway (2737)
  highway = track (2427)
  highway = path (1126)
  highway = residential (1123)
  highway = footway (858)
  highway = unclassified (843)
  service = parking_aisle (383)
  highway = steps (144)
  highway = tertiary (86)
  service = yard (51)
  service = alley (46)
  highway = pedestrian (42)
  service = emergency_access (35)
  highway = living_street (22)
  service = drive-through (20)
  highway = cycleway (19)
  highway = secondary (15)
  highway = rest_area (11)
...

No surprise that leisure=slipway on nodes is more popular than leisure=slipway on ways. As well no surprise that we have 2764 redundantly tagged ways and nodes which I wholeheartedly agree is to be avoided.

More interesting is that there are a large number of closed ways (1265) which are tagged as leisure=slipway. From a cursory glance most of of these seem to be tagging the linear slipway as an area rather than a line (which is inconsistent with the highway tagging in general.)

Also interesting is the high number of orphaned nodes (14745) not connected to ways at all. I’d be curious to dig into those. It’s better they exist than not exist for sure. I’m just curious their origins.

Overall, I think I’d come down on the ways of slipways as highway=service + service=slipway and to tag node at the water (or even in the water for tidal cases) as a leisure=slipway. It gives a full representation of the highway portion as a slipway, avoids redundant tags/POIs, and gives a clear indication of the slipway. There are probably cases where omitting the highway=service + service=slipway and only keeping the leisure=slipway on the node is also fine. (I think here about some remote dirt tracks that basically end at the water without really a defined slipway separate from the track.) This schema also makes connecting it to waterway=link easy to allow multi-modal routing.

Thanks again for taking on this project and sparking an interesting discussion.