A village no longer hides a mountain pass

Search for Twisty roads near the Tizi n'Tichka and the N9 over the pass is now on the list, with the RP1506 beside it. Mixed adds the RP2016.

What changed

Twisty and Mixed skip roads in built-up areas. Until today they did it by looking at the busiest point of a road: one village anywhere along it, and the whole road was gone. The N9 is 131 km long and crosses a village at 650 people per km², so Twisty (limit 150) dropped it. In Morocco almost every long road crosses a village.

Now a road is skipped only when it is built up for more than a quarter of its length. We sample the population every 250 m along every road and keep the level the road stays under for three quarters of the way. A long pass through a village or two stays in. A town street does not.

What it does elsewhere

We measured the rule in Morocco, Norway, Italy and Spain before choosing it. Twisty now finds about a third more roads in Morocco and Spain, half again as many in Italy and a tenth more in Norway, mostly long mountain roads that pass a hamlet. The Stelvio stays in, the Amalfi coast road stays out (it is built up for most of its length), and town streets stay out.

The limit you set in the advanced filters works the same way: it is the density the road stays under for three quarters of its length.

On the phone

The search on our server uses the new rule from today. Offline, the app uses it from its next update, with curvature tiles downloaded after today.