Estimate driving times?

[SmilerFTM]

I've noticed when planning road trips recently that the estimated travel time can vary massively from one mapping system to another. When using Nokia maps for my old Nokia it states the estimated travel time for one particular route I'm thinking of doing is 5 hours and 9 minutes, Google maps on the other hand states an estimate of 7 hours and 2 minutes while CoPilot GPS on my new Android phone gives an estimate of 9 hour 53 minutes. Problem is the route is on roads I do not know at all and so trying to figure out what the travel time will be and using these things as an estimate is proving difficult with such varied results. Anyone any idea what systems give the best estimates with regards to this at all?

[marshalla]

I've found that Google is always pessimistic (at least 10% over the actual time required), probably because it's trying to use traffic info. as it is at the time you produce the route plan.

[Wedg1e]

Simple solution based on data from my Garmin... over all the driving I've done on the last 70,000 miles with the satnav, my overall moving average is 48mph. A lot of that is on roads I've never driven. On that basis, divide the number of miles by 48 and that'll give you a good estimate.

[Dodsy]

My tom tom and built in car satnav usually agree to within a few minutes on any given journey. If I'm at a PC I use the route planner at www.theaa.com , its usually within a few minutes of the tom tom time as well although it can choose some peculiar routes.

[DIW35]

Wedg1e said:

Simple solution based on data from my Garmin... over all the driving I've done on the last 70,000 miles with the satnav, my overall moving average is 48mph. A lot of that is on roads I've never driven. On that basis, divide the number of miles by 48 and that'll give you a good estimate.

As a rough guide, and to make the maths easier to do in your head, I have always divided the journey distance by 50 to give me a ball park time which is usually close enough. Just remember to factor in any stops you plan to make.