According to a study cited by the UMKC team, the incidence of headphone-wearing pedestrians being injured or killed has increased by 300 per cent in the last 10 years.
Not only does the content being played through a pedestrian's smartphone or iPod distract them from the their environment, but it effectively blocks out many of the audio clues, including honks, engine and road noises, that would otherwise alert them to danger.
Developed for Android, the WiFi-Honk app works by communicating with other cars and pedestrians running the app, and figuring out whether there's a chance of a collision. If there is, the app will inform all involved parties via both visual and audio alerts.
Current proposals for vehicle-to-vehicle and vehicle-to-infrastructure communication require the use of special frequencies designated for dedicated short-range communications (DSRC). Retrofitting this capability to existing cars would be prohibitively expensive and doesn't account for pedestrian traffic.
Instead of using DSRC, WiFi-Honk utilises regular ad-hoc wireless network technology. Under normal circumstances two devices on a Wi-Fi network can't communicate with each other if they travelling over 8km/h. As well, setting up an ad-hoc wireless networks requires a not insignificant amount of time — certainly more than an imperilled pedestrian or vehicle might have.
To get around this, WiFi-Honk "hacks" the beacon sent out by wireless networks to include information about a user's speed, distance and heading. Typically these beacon signals only contain info about a network's vital details, and it's how your phone, laptop or tablet can find wireless networks to connect to.
Using beacon signals WiFi-Honk can work at speeds up to 120km/h, as well as broadcast a car or pedestrian's location, direction and speed every 100ms or more. Unlike current in-car pedestrian detection systems, WiFi-Honk doesn't require line of sight and could, say, detect a person walking out onto a street from behind a truck.
Currently the WiFi-Honk app must be started up on a smartphone by pedestrians, as well as drivers, before they set off on their journey.
WiFi-Honk has been tested successfully on the UMKC campus, but is still a long from being let loose into the Google Play app store.