The solution
WIRED reported in 2018 that Chicago's multi-level downtown streets, such as Lower Wacker, are where GPS signals die. Waze engineer Gil Disatnik started the project in Boston in 2014 after getting lost twice leaving a tunnel. His first idea, WiFi access points, failed because speeding cars do not latch onto WiFi. He switched to beacons that emit Google's Eddystone format, each broadcasting specific coordinates about ten times a second, so any device can locate itself.
With one beacon about every 130 feet, the setup costs about $1,100 a mile to install. Chicago parking app SpotHero, tired of tech-supporting customers lost on the way to lower-level garages, bought 500 beacons and gave them to the Chicago Department of Transportation to install. Chicago was harder than Boston's simple tunnels: roads turn, some stretches are semi-open so some beacons went on roofs or poles, and beacons cannot register altitude, so Waze relied on beacon-specific identification and best guesses to tell which level a driver is on.
Why it worked
GPS needs line of sight to satellites, which tunnels and double-decker streets remove.
Beacons are cheap per mile and run on an open signal standard, so other apps can use them too.
SpotHero profits when drivers reach garages and lose support time when they get lost, giving it a reason to pay.
The city benefits because lost drivers stop traffic while they get their bearings, per a transportation department spokesperson.
What can be applied
When a shared infrastructure gap hurts a partner's business, let that partner buy the fix and the city install it.
Aftermath
As of September 2018 the multi-level streets were studded with the beacons and the article says it works by and large. Waze beacons were already in Pittsburgh, with another big US city pending. A former Chicago transportation commissioner called it a high-value, low-cost implementation. Not every lower road was instrumented, and the article offers no measured reduction in lost drivers.
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