A crowd-sourced navigation app will soon help drivers avoid left-turns and difficult intersections. Waze is also getting a test feature to avoid high-crime areas.

The Google-owned app combines traditional mapping and live traffic data with user reports of crashes, temporary road closures and other factors that may affect the optimum route at a specific time.

According to the people behind the app, Los Angeles is particularly notorious for having intersections where a left-turn is stressful and difficult, for example because of end-to-end traffic, a lack of traffic lights, or blocked visibility.

While it might seem as if “never turn left” is a simple enough instruction — CNET notes that UPS has had it as driver policy for more than a decade — it seems it’s not so easy to automate it in navigation systems. Instead Waze has asked local staff and customers in LA to draw up a list of the most troublesome intersections and the best workaround routes. If the feature works as planned, it hopes to roll it out to New Orleans next and then onto other cities where there’s a particular need.

Meanwhile another Waze test in Brazil will warn users if a route will send them through a high-crime area. The company says it will use verified crime report data rather than rely on individual impressions of which areas are unsafe to drive through, though it may enhance this with user reports of police presence. The test may be in place in time for the Rio Olympics when the number of out-of-town (and foreign) drivers will likely rocket.