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Does Google Maps use Speed Limit to calculate ETA?


When the user creates a new route in Google Maps, the app calculates an estimated time of arrival at the final destination. This estimated time is often correct, but sometimes it's not clear what time Google Maps is targeting when calculating it. There is an assumption that Google Maps uses the speed limit. Is this true? Let's find out.

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To answer briefly, Google uses for its calculations not only the speed limit set on a particular stretch of road, but also the user's GPS. When you drive, your position changes relative to satellites. Google Maps uses this data to adjust your speed every few seconds. The same ETA methodology is also used by other navigators.

What data does Google Maps use to calculate ETA?

The main source for ETA calculation is the average speed. These readings have a fixed value and do not change that often. Using the average speed, Google Maps displays an estimated time of arrival for the driver.

Additional factors that affect the estimated arrival time:

  • The length of the route
  • The traffic situation on the road
  • The current average speed of the vehicle

Although several factors are used to calculate the ETA, the speed limit is still the fundamental parameter. When you create a route, these figures are available to the Google Maps app initially. They are then adjusted as the vehicle moves.

How does Google Maps get information about speed limits?

There are several ways to collect information that is stored in Google databases and then used to calculate ETA. Let's list the main sources of data about set limits:

  • Waze (owned by Google): wazers correct information and send up-to-date data to Google
  • data from Google Street View: For several years Google has been collecting information on the roads with its cars all over the world
  • information available publicly and worlwide

So the Google Maps app takes information from multiple sources, aggregates it, and then uses it to build routes and calculate final arrival times.

Does your current driving speed affect your distance time?

Google Maps users note that the arrival time to the destination can be different from the original arrival time. This is usually due to the situation on the road: traffic jams, road accidents, repair work. As a result, the app corrects the time of overcoming the distance and the time of reaching the finish line.

Google Maps requires a GPS connection with satellites, and the app actively uses the user's location to understand at what speed he is moving and to correct the route. Adjustment of the route happens all the time.

The fact is that the speed limits are not always a guide for Google Maps, as many drivers exceed the maximum allowed speed, or reduce it for safety reasons, or because of the difficult situation on the road.

Does Google Maps inform the user about speed limits?

Generally speaking, speed limits on Google Maps are used to warn the user that they have exceeded the speed limit and that it threatens safety. This feature of the app is very important.

If the user has enabled this feature through the navigation settings, Google Maps displays a speedometer icon and speed limits in the bottom right corner of the screen. The online speedometer calculates your current speed using GPS satellites. By comparing the current speed to the allowed speed, Google Maps informs the driver how much he or she is deviating from the allowed speed limits.

Does Google Maps notify you about Speed Traps on the roads?

Probably, if there were no Speed Traps, speedometers would not be so important in GPS navigation. In areas where there are Speed Traps, drivers are more careful to make sure the speed limit is not increased.

Yes, in some areas, Google Maps notifies the user that there is a chance of hitting a speed trap. It works similarly to the Waze app.

It is necessary to activate this function through the settings of the navigator. As a result, when approaching a speed trap, Google Maps displays a notice and plays a sound signal. This allows the driver to reduce speed in time and get ready for the speed trap.

Ilia is a professional writer. He has expert knowledge in GPS and cartography with 15 years of experience. Additionally, Ilia has extensive experience in data recovery on PC and mobile. He started his career as a journalist by reviewing PC and mobile apps. His current responsibilities are to keep track of users' questions on MGT and answer them.