Show HN: I made a website to find best bus seat to avoid the sun while traveling
A hobby project called SitInShade uses mapping data and solar position calculations to tell bus passengers which side of the vehicle will be shadier during a given trip. Commenters praise the simplicity and utility of the idea, while probing its technical underpinnings, such as using OpenStreetMap routes, computing sun azimuth without external APIs, and handling edge cases like tunnels, ferries, and long multiday journeys. Many suggest extensions to trains, flights, walks, and stadium seating, along with UX tweaks and options for those who actively prefer sitting in the sun.
Overall reaction
- Many commenters found the idea charming and “small but meaningful,” praising it as a well‑executed hobby project.
- Several noted relief at not needing a mobile app; a simple website that works globally was appreciated.
- Some saw commercial potential (e.g., integration into ticketing sites) but the project is generally perceived as non‑commercial.
Use cases and demand
- Frequent use cases: hot buses with poor AC, motion sickness or migraines triggered by strobing light, eye sensitivity, skin concerns, and keeping babies comfortable.
- People also want versions for flights, trains, cars, ferries, stadium seating, city walks, and hiking (e.g., integrating with AllTrails).
- A minority expressed confusion about why shade matters; others replied that direct sun makes sleeping, working, or long rides unpleasant.
Technical approach & challenges
- Routing currently relies on OpenStreetMap; for flights there is a beta at
dev.sitinshade.com/flight, with manual flight-duration input. - The author reports computing solar azimuth/altitude etc. on the backend (Node.js) without external solar APIs, using bus orientation over time.
- Commenters point to known solar-position resources (NOAA spreadsheets, pvlib, SunCalc, astronomy libraries) and discuss accuracy vs. “good enough.”
Limitations, bugs, and data issues
- Major limitation: routing uses road/car directions, not actual bus or train routes; this can diverge significantly (e.g., bus‑only bridges, ferries, Channel Tunnel).
- Some trips appear wrong to users (e.g., France routes, Western Australia example, Toronto–Montreal side choice, JFK–Heathrow yielding a Lisbon route).
- Edge cases include extreme latitudes (Iceland showing 0% sun), timezone confusion, and odd autocomplete behavior.
- Critics argue it’s trivial for “oriented” people; others counter that road curvature, time of day, season, and hemispheres make intuition unreliable.
Feature requests & UX feedback
- Requests: 24‑hour time, local timezone by origin, ability to add waypoints or customize route, train/rail support, stadium and city‑walk planners, sun‑side vs shade toggle.
- UX notes: red “preferred side” color feels like “don’t choose”; seat‑side colors could be more consistent.
Broader discussion
- Thread spins into explanations of sun paths by latitude/season, hemisphere differences, and even etymology of “posh.”
- Health subthread covers UV through glass, myopia and outdoor light exposure, and sunscreen/UV trade‑offs.