Find the flattest route between any two points in SF
- ID
- 32166
- Status
- summarized
- Published
- 06 Oct 2026, 5:40 AM
- Fetched
- 06 Oct 2026, 3:15 PM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://flattensf.com/
- Source URL
- https://hnrss.org/best
Summary
- Score
- 6.0
- Created
- 06 Oct 2026, 3:16 PM
- Tags
- Audience
- developersvibe_coders
What happened
Drew Edwards' Flatten SF is a browser-based tool that finds flat routes between any two points in San Francisco by computing over 160,000 street segments with USGS 1 m lidar elevation and the Overture/OpenStreetMap street graph. A slider exposes the trade-off between shortest and flattest routes, treating a foot of climb as costing 200 ft of walking and using cumulative elevation gain; stairways are allowed on foot but excluded for bikes, and place search is built in offline. The Hacker News discussion has 162 points and 54 comments.
Why it matters
For builders, the reusable piece is the client-side architecture and the explicit distance-vs-climb trade-off, not the SF-specific dataset. If you work on maps, routing, or local utilities, study how 160,000 segments and offline place search run in-browser; Malaysian builders would need to check whether equivalent open elevation and street data exist before adapting it to hilly local areas.
Discussion angle
What would it take to adapt this browser-only lidar/OSM routing pattern to a hilly Malaysian city, and which open datasets or data gaps would determine whether it is practical?