How it works

Risk, weighed before you drive.

Tsamaya puts a risk check on top of ordinary turn-by-turn routing. Here is the whole thing, from the moment you pick a destination to the route on your screen.

The six steps

From destination to lower-risk route

  1. 01

    Fetch the fastest route

    We start with an ordinary Mapbox route, the same quick line any map app would hand you. That is the baseline everything else is tested against.

  2. 02

    Test it against the rated areas

    The route is sampled along its length and tested against every rated area, using the ratings for this hour. Only high-risk (red) and elevated (orange) areas count. Yellow is shown on the map but never forces a detour.

  3. 03

    Already on a checked road?

    Where the route already runs along a road we have checked through an area, that counts as passing through, and no detour is needed. Checked roads are the local knowledge that stops the app over-reacting.

  4. 04

    Find a way round

    For the areas the route still runs through, Tsamaya picks a nearby checked road and adds a few waypoints, nudging the route around the area rather than through it.

  5. 05

    Re-route, then sanity-check

    The route is fetched again through those points. A detour is only offered if it cuts your exposure, and one that adds too much distance is thrown out. When there is no good alternative, you get the normal route with the risky stretches marked. It will not invent a detour to look busy.

  6. 06

    Drive it

    Follow it in the app, turn by turn with voice, on your phone, Apple CarPlay or Android Auto. Or hand it to Google Maps with the detour points already in place, so it follows the same line.

Try it

Route it yourself

Tap a start, then a destination, anywhere on the city. The straight line goes in grey; if it crosses high-risk cells, the lower-risk way round goes in emerald. Switch the ratings to Night: some trips only bend after dark.

Ratings for

Or pick a trip

Tap a start point on the city.

A toy version of the idea · The app uses real roads, real ratings and a limit on detours

Rated by the hour

Three ratings for every area

Every rated area carries a rating for each part of the day, and the app reads the clock: there is no switch to get wrong.

Daytime · 05:00 to 17:30
Most areas sit lower in the daytime. Plenty of roads that carry a penalty at night carry none at midday.
Evening · 17:30 to 19:30
The two hours when the day's ratings give way to the night's: rush hour, and the light going.
Night · 19:30 to 05:00
Ratings climb after dark. A dark intersection is a different proposition from a lit one.

Yellow means caution: it is shown on the map but never forces a detour. The lowest band means an area was checked and carries no routing penalty, which is different from an area we have no data for.

Get the app

See it on your own roads.

Google Play · open test

Android

Join the open test on Google Play, then install it like any other app.

Get it on Google Play

TestFlight · beta

iPhone

Apple's TestFlight app installs beta apps. Get it first, then open our invite.

Join on TestFlight

Go deeper

The screens, and the machinery

Walk through the real app, or read the rules that decide a detour.

See it in action Technical details