Recommended Free Tools
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Google Maps estimates what is happening on the road by combining anonymous phone-location data with traffic and incident information from other sources, including licensed partner feeds. During navigation, it can also use GPS location, route details and device sensor data. Users’ incident reports add information about specific disruptions. Google describes these inputs publicly, but does not disclose a complete prediction formula or a quantified ETA accuracy rate.
How Google Maps estimates traffic
Google says anonymous data from phones helps it pinpoint traffic jams when location data collection is turned on. It combines these observations with traffic and incident data licensed from partners such as governments, non-profits, schools and businesses. Travel-time estimates draw on location data from the past and present, as well as other sources.
These inputs serve related but distinct purposes: phone movement can help indicate how traffic is flowing, while partner information can contribute traffic and incident data. Google does not identify specific suppliers or publish how much each source contributes, so the relative weight of the inputs is not established.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minuteWhat information navigation can use
Google says that during turn-by-turn navigation, Maps may use GPS location, route details and device sensor data, such as barometer readings. It can use this information alone or combine it with other information to improve navigation, suggest faster alternatives and show real-time traffic, disruptions and weather.
#1 Best Overall
- Bright, high-resolution 5” glass capacitive touchscreen display lets you easily view your route
- Get more situational awareness with alerts for school zones, speed changes, sharp curves and more
- View food, fuel and rest areas along your active route, and see upcoming cities and milestones
- View Tripadvisor traveler ratings for top-rated restaurants, hotels and attractions to help you make the most of road trips
- Directory of U.S. national parks simplifies navigation to entrances, visitor centers and landmarks within the parks
According to Google Maps Help, collection for turn-by-turn navigation starts shortly after you tap Start and ends when you arrive or exit navigation. Google describes navigation data as helping provide real-time features, including traffic conditions, disruptions and faster-route suggestions.
How the different information channels fit together
| Information channel | What it can contribute | What it does not establish |
|---|---|---|
| Aggregated phone movement | Observations that help Google identify congestion and estimate travel times. | Google does not publish the relative contribution of this data or an ETA accuracy figure. |
| Licensed partner data | Traffic and incident information from sources such as governments, non-profits, schools and businesses. | Google does not name specific suppliers in the described sources. |
| User incident reports | Reports about specific disruptions, with nearby users sometimes asked to confirm whether an incident remains. | Available report categories and features vary by country or region. |
| Partner dash-camera imagery | Short, silent clips licensed from trusted third parties to help detect or verify certain map changes, such as speed-limit updates and new traffic signs. | This is not evidence that an individual dash camera sends Google a live feed of congestion. |
How incident reports appear on the map
Maps users can report road incidents. During navigation, a report from another user may appear as a driver nears the reported location. The nearby driver may see the prompt “Is this still here?” and can indicate whether the incident remains.
Rank #2
- 6” high-resolution navigator includes map updates of North America
- Hands-free calling when paired with your compatible smartphone with BLUETOOTH technology and convenient Garmin voice assist lets you ask for directions to places you want to go
- Road trip–ready features include the HISTORY database of notable sites, a U.S. national parks directory, Tripadvisor traveler ratings and millions of Foursquare POIs
- Driver alerts for things such as school zones, sharp curves and speed changes help encourage safer driving and increase situational awareness
- Access live traffic, fuel prices, parking, weather and smart notifications when you pair this navigator with your compatible smartphone running the Garmin Drive app
Report categories and availability vary by location. Google advises users to report incidents only when it is safe to do so; do not handle a phone while driving.
How to read traffic colors and incident symbols
- Green: no delays.
- Orange: medium traffic.
- Red: delays; darker red indicates slower traffic.
Icons mark reported or mapped events such as crashes, construction and road closures. Traffic information is not available everywhere, so a missing traffic line or incident marker does not prove that a road is clear.
Rank #3
- Explore confidently with the reliable handheld GPS
- 2.2” sunlight-readable color display with 240 x 320 display pixels for improved readability
- Preloaded with Topo Active maps with routable roads and trails for cycling and hiking
- Support for GPS and GLONASS satellite systems allows for tracking in more challenging environments than GPS alone
- 8 GB of internal memory for map downloads plus a micro SD card slot
What Google says about privacy
Google says it combines anonymous phone data with data from other phones so that a device cannot be singled out, and that starting points and destinations are permanently deleted. Its navigation-data page also says needed navigation data is deleted after processing and that map updates are not associated with a Google Account or device.
These are Google’s descriptions of its practices, not independent privacy-audit findings. The reviewed pages do not quantify privacy outcomes.
Rank #4
- 8” navigator with high-resolution, dual-orientation display and map updates of North America .Special Feature:Large Display; Voice Assist; Hands-Free Calling; Live Traffic and Weather; Traffic Cams and Parking; Smart Notifications,Driver Alerts; Tripadvisor; National Parks Directory; Find Places by Name; Garmin Real Directions Feature.
- Hands-free calling when paired with your compatible smartphone with BLUETOOTH technology and convenient Garmin voice assist lets you ask for directions to places you want to go
- Road trip–ready features include the HISTORY database of notable sites, a U.S. national parks directory, Tripadvisor traveler ratings and millions of Foursquare POIs
- Driver alerts for things such as school zones, sharp curves and speed changes help encourage safer driving and increase situational awareness
- Access live traffic, fuel prices, weather, parking and smart notifications when you pair this navigator with your compatible smartphone running the Garmin Drive app
What dash cameras have to do with Maps
Google says it licenses short, silent video clips from trusted third-party companies that collect imagery using commercial and consumer dash cameras. Google describes using these clips to detect and verify real-world map changes, including speed-limit updates and new traffic signs, and says it does not publish the imagery.
This is a separate map-detail update process. It should not be confused with the phone and partner data used to estimate traffic, and it does not mean an individual driver’s dash camera supplies live congestion information to Google Maps.
Best Value
- Bright, high-resolution 5” glass capacitive touchscreen display lets you easily view your route
- Get more situational awareness with alerts for school zones, speed changes, sharp curves and more
- View food, fuel and rest areas along your active route, and see upcoming cities and milestones
- View Tripadvisor traveler ratings for top-rated restaurants, hotels and attractions to help you make the most of road trips
- Directory of U.S. national parks simplifies navigation to entrances, visitor centers and landmarks within the parks
What Google has not disclosed
The public descriptions identify broad categories of input, but they do not provide a full forecasting algorithm, name specific traffic-data suppliers, quantify the contribution of each input, or give an independently measured ETA accuracy rate. There are no supported figures here for traffic-data volume, incident counts or quantified privacy outcomes. An ETA is therefore an estimate based on the available inputs, not a published accuracy guarantee.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
