In the war between bikes and cars, cars definitely have the advantage. They’re bigger, they’re more dangerous, and they’re able to argue that they “just didn’t see” cyclists hovering in their blind spot.

This last factor, though, could be about to change. Bikeshield, a new app, allows car drivers to detect and track motorcycles and bikes before they’re visible in rearview mirrors. If it works, it could prevent them from swerving or making unexpected turns as a cyclist draws alongside.

Here’s how it works. You tell the app whether you’re aboard a bike, motorcycle, or car. It automatically activates when you start driving by detecting that you’re suddenly moving very fast. Then, it makes a noise five or 10 seconds before a bike or motorcycle passes you to let you know they’re coming. Clever.

The app’s developers decided that audible notifications would be distracting to those on two wheels, however: with cyclists and bikers, it contents itself with warning those around you that you’re there.

The app’s creators hope it’ll make cycling safer, and increase the number of bikes on the road. But there is one fairly big drawback: for the app to work, both driver and cyclist need to have it installed. In other words, its success relies on it being taken up from a high number of road users.

To tackle this, the app will be free when it’s released on 12 September; its developers have put together an “ambassador” scheme through which cyclists and drivers spread the word, too They also plan to team up with insurance companies so car users get it as part of an insurance app.

Pere Margelef, one of the app’s designers, told Fast Company that the app is a kind of stop-gap until cars themselves are self-driving or are equipped with their own sensors:

“In 10 years, cars may be driving themselves and preventing accidents. But that’s too late. I’m riding my bike and motorcycle now, and I want to fix the problem now.”

Considering that Google’s self-driving cars still can’t operate in the rain, we may be needing apps like this for a little while yet.