How traffic jams show up on Google MapsGoogle Maps continually refreshes based on anonymously tracked user data, traffic sensors, and satellite data to make sure the app is displaying the most accurate traffic conditions possible. If you’ve ever used Google Maps, you’ve likely seen streets colored green, orange, or red. Green roads mean traffic is moving normally, but orange and red represent slowdowns. Slowdowns show up when users in navigation mode are currently traveling at slower-than-usual speeds on that part of the road and are applied by Google automatically. However, once other divers using Google Maps are able to get through the area at normal speeds, Google will remove the slow down status for that area—even if other users are still driving slower. It’s unclear how many slower-than-usual users are necessary for Google Maps to register it as slow traffic, but according to 9to5Google’s report on Weckert’s traffic jam experiment, it only took a single car driving past him at normals speeds to undo the traffic jam status caused by his wagon of iPhones. That said, it appears that Google Maps ignores when lots of users are at a standstill. Weckert’s wagon had to be moving in order for Google Maps to see the traffic jam—even though nearly 100 phones were in navigation mode and not moving. How long a vehicle must be idling before it’s ignored is unclear; obviously, Google Maps will notice if several users are stopped on a highway and report it as a slow down, but if a bunch of people are parked in a parking garage and just happen to have navigation mode on, then you probably won’t see any traffic jams listed in the area. Interestingly, not all vehicles are treated equally. Google Maps can tell the difference between a car, motorcycle, and other vehicles (at least in certain countries and regions). So even though a cheeky scooter might be able to weave its way through a traffic jam, Google Maps could—in some cases—recognize that the smaller vehicle’s movement doesn’t necessarily mean that regular traffic conditions have resumed.
Accidents, construction, and other traffic incidentsGoogle Maps also updates traffic reports based on user input in addition to passive, anonymized location and movement tracking to help keep conditions updated. Accidents, construction zones, speed traps, and other alerts can all be reported in Google Maps, and the more users that report an alert help it show up faster on the map for others and potentially help them avoid slowdowns and find better routes if necessary. We’ve previously covered how to do this on both Android and iOS, but here’s how to report traffic incidents and slowdowns in Google Maps if you’re unfamiliar:
- While in Google Maps’ navigation mode, tap the “+” icon (third icon down on the right-side menu).
- Tap the icon for the type of incident you wish to report. Follow the on-screen instructions to finalize the submission.
- The app will begin adding the report to the map, though you have a short countdown window to undo the report if you want to cancel.