I have a long daily commute, usually two to three hours behind the wheel, and I use Waze every day. I'm based in the UK, but I think the issue below applies anywhere Waze operates.

The problem is how Waze reroutes around congestion. As soon as there's heavy traffic or a road closure, it drops me from major roads onto very minor ones: narrow single-track lanes where traffic in both directions shares one lane, often with no street lighting and no passing places. My car is mid-size and these lanes are simply too narrow for it. At night I've hit kerbs and roadside stones several times, and I've already shattered the underbody protection plate on my car. That's a real safety issue, not just an inconvenience.

The underlying gap is that rerouting seems to optimise almost entirely for time saved, and treats a minor road as interchangeable with a major one if the ETA is a few minutes better. For a lot of drivers it isn't. I would rather sit in a jam than be sent down a lane like that. If the choice is being late for work or risking my safety, I'll choose being late every time.

Two suggestions:

1. When recalculating a route because of congestion or a closure, weight road class much more heavily. Keep the driver on major roads unless the delay saved is substantial, rather than diverting onto minor roads for a small time gain.

2. Add a user preference along the lines of "Prefer major roads", so drivers can choose to stay on higher-class roads even when the route is longer. This would need to map onto each country's own road classification. In the UK that's motorways (M) and A-roads versus everything below, and most other countries have an equivalent hierarchy that Waze presumably already holds in its map data.

The second suggestion in particular looks straightforward to implement on top of data you already have, and would make a genuine safety difference.