02 In detail
How digital emergency vehicle alerts work
Lights and sirens give drivers a few seconds’ notice. A digital alert on the screen they’re already looking at gives them more. Both HAAS Alert and Blue Light Alert are built on that idea, and both deliver through Waze. Independent research shows warned drivers react earlier and more smoothly. We’ve summarised it on the Blue Light Alert page.
The difference is the information each alert is built from.
What HAAS does well
It doesn’t depend on navigation. HAAS triggers from the vehicle’s lights, through a transponder or a telematics platform. Any vehicle with the lights on can generate alerts, whatever the crew is using to get there, and so can a vehicle parked at the roadside.
It reaches more screens. As well as Waze, HAAS alerts appear in connected vehicles from Stellantis, Škoda and others. Blue Light Alert only reaches Waze drivers today.
It’s widely deployed. HAAS reports thousands of agencies, mostly in the US, and has announced fire and ambulance services in Europe among its users.
Why route-based alerts reach drivers sooner
Every digital alert has to travel. It goes from the vehicle to a server, from the server to the navigation provider, and from there to each driver’s phone. That takes time. Meanwhile, an emergency vehicle on blue lights is covering ground much faster than the traffic it’s warning.
An alert built from where the vehicle is has to win that race. By the time it arrives, it describes where the vehicle was. Drivers notice. On Waze’s community forum in April 2026, one wrote: “By the time the notification has been made, the vehicle has moved!!!” A few days later they added: “I actually saw an ambulance turn onto the road ahead of me and then got the warning.”
Blue Light Alert starts from somewhere else. When a crew starts navigating to a call in Blue Light Maps, we already know the route they’ll take. That means we can place the warning on the roads ahead of the vehicle before it gets there, rather than chasing its position. And because we know the route, we warn the drivers on it and leave alone the ones on a parallel road who were never in the way.
When HAAS Alert is the better fit
Blue Light Alert needs the crew to navigate in Blue Light Maps. If a vehicle goes to a call without it, there’s no route and no alert. HAAS will still fire from the lights. If your crews won’t use our navigation, or if most of your risk is vehicles parked at the roadside, HAAS may be the better fit.
For crews who are navigating anyway, it’s the same app doing both jobs. It finds the faster route using their exemptions, and it warns the drivers on that route. Blue Light Alert is included with Blue Light Maps, so there’s no second subscription to budget for and no transponder to fit in every vehicle.
Seeing it in your area
You can download the Blue Light Alert evidence brief. We can discuss further in a 30-minute walkthrough, then trial in your own area with your own crews, and no commitment until you’ve seen it working.