About this route

The Lantern path is a better-lit, potentially busier walking route than the fastest way. It is not a safer route — no app can promise that. It simply makes a different trade-off: it leans toward streets that tend to be lit and to have people around, usually for a small amount of extra time. You always see the fastest route too, and the choice is yours.

Better-lit, potentially busier — not “safer”

Lantern never labels any street or area as dangerous, and it never routes you away from a neighbourhood. It only nudges toward streets with qualities that many people find reassuring at night. Treat it as one input to your own judgement.

Exactly what goes into choosing it

By day, the Lantern path is simply the shortest sensible walking route — lighting, busyness and crime have no effect at all. In the evening and late at night, every street segment is given a preference score built from these factors:

Lighting — from real OpenStreetMap lit tags. Lit streets are preferred (×1.25); streets tagged as unlit are de-preferred (×0.55); untagged streets fall back to an estimate from the road type.
Open venues nearby (“eyes on the street”) — shops, cafés and pubs that are open at your departure time, from OpenStreetMap opening hours. Up to a +25% preference where venues are open.
Road type — main and through-roads and pedestrianised streets are preferred over isolated paths. Steps and tunnels are strongly de-preferred (×0.5).
Transit proximity — being within ~180 m of a station gives a small boost (×1.08): somewhere to head for.
Reported crime — police.uk street data (monthly, anonymised; only violence, robbery and anti-social behaviour). It applies a small capped nudge (at most −15%) that can never remove a street from consideration, and it has no effect during the day.
Late-night intensity — after ~11pm, the pull toward lit, active streets is strengthened.

The route chosen is the one that minimises total (street length ÷ preference) from start to destination, capped so the Lantern path never adds more than your detour limit versus the fastest route — otherwise it falls back to the fastest route and tells you so.

The lighting figure shown for a route (e.g. “82% of this route has real lighting data”) is the share of the path covered by genuine OpenStreetMap lighting tags — the rest is estimated, and we say so.

What it deliberately does not do

It never produces a “danger score” for any area, and never shows one on the map.
It never routes you away from a neighbourhood — only toward better-lit, busier streets.
It never calls any route “safe.” Busyness is an estimate, not measured footfall.

One input to your judgement

Lantern is informational and does not track you or summon help. In an emergency, call 999. For the full data sources and privacy details, see the About page.