Because navigation uses big data, it is based on a large number of previous driving records to give a fair time. And the navigation also marks congested routes, so surely it will count the traffic jam time as well.

The distance on the navigation is based on the maximum speed limit of the road at the time. For example, if you're traveling 10 kilometers on a road with a speed limit of about 60 mph, you'll be able to get to the top of the road and get to the bottom. Then the navigation will be based on the long distance according to the highest speed limit standard to calculate the approximate time with you. So the distance in kilometers should also calculate the arrival time, also according to the speed limit to calculate. If there is a traffic jam, the navigation will also increase the time up because it detects a traffic jam.