The travelling times provided are as a guide only. Route times are calculated using a number of factors, but primarily using the signed speed limit for each section of road in conjunction with the types of turns required to complete the journey.
It is important to note that the calculated time does not take into account stops that you should take on the journey to ensure alertness, or your specific driving situation (e.g. you are driving a speed limited vehicle).
Additionally, road works, weather conditions and other road speed variations that are put in place are not generally taken into account.