Driverless cars are on their way. In the meantime, iPhone app Nexar aims to improve human driving by recording and flagging hazardous cars on the road.

Nexar monitors the traffic around your car using the camera on your iPhone, and whenever it suspects dangerous driving, it invites you to record the incident and flag the offender as a bad driver.

To use the app, the iPhone must be mounted on the front dashboard of the car with the rear camera toward the windscreen. Nexar uses machine vision and motion sensing to monitor the movement of your vehicle and the traffic around you.

Whenever it detects an incident – such as a sharp slamming of the brakes, or a speeding vehicle – a pop-up appears on the phone, asking you if something happened. If you tap the screen to indicate yes, Nexar records video footage from 20 seconds before the incident up through 10 seconds afterward. The license plates of the offending vehicles are also recorded and uploaded to a central database. If the driver of one of these cars is using Nexar, he will be notified that he has been identified as a bad driver.

Eventually, Nexar plans to warn users of dangerous drivers nearby, flashing the license plates of repeat offenders at the bottom of the phone display, whenever their registration is spotted by the camera. Unlike other apps, Nexar doesn't use battery-draining GPS. Instead, Nexar uses the phone's gyroscope, accelerometer and compass. From that input, it interprets location data and other information.

The Nexar app was launched into public-beta by the Israeli startup of the same name at the Code Conference in Rancho Palos Verdes outside L.A. on May 27, and it has already raised a few eyebrows. As CEO Eran Shir demoed the app, Re/code's conference presenter Walt Mossberg quipped that this was "an outrageous invasion of the privacy of bad drivers."

"This is an outrageous invasion of privacy and bad driving" @waltmossberg on @Nexar demo #CodeCon

— Julia Boorstin (@JBoorstin) May 27, 2015

Certainly there are privacy issues here, but the app also seems to have a number of other problems. The user is able to report bad driving whenever she likes, and could easily blame an "incident" on another vehicle when she may have been the one at fault. This kind of abuse could lead to a completely flawed database of bad drivers.

Shir claims that Nexar could help drivers deal with road rage by reporting an incident rather than lashing out, but there's as much opportunity for the app to cause conflict. Users who see themselves flagged as bad drivers in real time are unlikely to be pleased and may well react worse to this telltale approach than they would to being cut off at a junction.

There's also the issue of what Nexar would do with the collected data. Would it be passed on to insurance companies to penalize the "bad drivers?" Shir also claims that Nexar won't distract drivers — but this is hard to believe. Even tapping on the phone screen to start recording could take a driver's eye off the road, and trying to read flashing license plates at the bottom of the phone's screen would be a significant distraction.

Nexar is free to download on iOS and will start testing on the streets of L.A. and Tel Aviv from May 27.

Photo: Aaron Parecki | Flickr