Estimate your arrival time from the distance, average speed, start time and breaks.
Traffic, weather and road conditions can change the real time.
It assumes a steady average speed. Traffic, tolls and weather will change it.
Yes, it shows +1 day if you arrive after midnight.
Highways often average 50–70 km/h once stops and traffic are included.
No. Everything is worked out in your browser and nothing you type is sent to a server.