google maps/navitime time duration

Hello all,
I am currently putting together an itinerary for a trip to Hokkaido and have been using google maps and navitime to get distance and duration from place to place by car.
Somehow, the indicated durations seem a little long and I remember from past car trips that it usually goes a lot quicker than what the satnav says.
For example, Abashiri to Sounkyo is indicated as 130km and 2h30min on overland highways, or Chitose Airport to Obihiro (by expressway only 160km) is indicated as 2h10.
I would have expected something like 1h45min for those routes and was wondering if anyone can recommend a more reliastic navi site or give me a feedback if I'm completely wrong here..
Thanks everyone in advance!
Felix

Isn't the speed limit for most of the route (national highway) 60km/h?

In my experience I am usually faster than the Navi thinks I should be. Does that mean I am speeding ? Well, yes from time to time , but I do agree that the Navi times are on the conservative end.

Enjoy your trip to Hokkaido!

My unscientific, untested, conclusion is that the satnavs (and, I imagine, Google, etc) will only use a max speed equal to the speed limit....which makes their estimates for journeys on rural roads (speed limits of 50-60 kph) quite long.

This is what I've always found, but it's anecdotal.

The airport to Obihiro from memory is a 50 km/h road which is quite nice and can be driven at 60/70 km/h at times. Many locals do speed in the countryside - but that's a story for another day.

In general, I find satnavs and google maps to be kind of correct, but are as stated a bit on the conservative side. I do find they are more conservative in Hokkaido as there tends to be less traffic there than say Honshu....

google maps factors in traffic and real-time results from other drivers who have google maps installed on their phones while driving that route. So if it is saying longer than you would expect, it may be traffic or road conditions.

Neither Google nor Navitimes gives a big difference,
but Google tends to be calculated at a clearly faster average speed.

However, in Hokkaido excluding urban areas where few signals,
the time estimated by Google is often more realistic.

In Hokkaido, there is a famous website "Northern Road Navi" long before smartphone navi spread.
http://northern-road.jp/navi/eng/index.htm
For calculation to move between major cities or spots, try this.
This local web calculation data base made by official raod management divisions,
and they said in ordinary road average speed is using "50km/h(= 31mi/h)".
http://northern-road.jp/navi/time/time_info.htm
If first time, you should read their PDF(traffic rules, basic tips and more) all.
http://www.hkd.mlit.go.jp/topics/toukei/chousa/h20keikaku/e/e_all.pdf

And Express way management company "NEXCO EAST(Higashi-Nihon)" has a online calculator,
but no EN menu, only in Japanese.
https://www.driveplaza.com/traffic/
https://en.driveplaza.com/expressways/
They also provide discounted "Hokkaido Expressway Pass".
https://www.driveplaza.com/trip/drawari/hokkaido_expass/en.html

Many local and Japanese drivers often faster than speed limit is right, be carefull.
https://youtu.be/PfqUILoUlU4
The enemies of driving in Hokkaido are especially self-control, traffic police and wild animals.
https://youtu.be/SjqzIkmmqnU
https://youtu.be/4tC5j6qRudM

Google over calculates times as they dont use speeds above 80kph.

I find google times spot on when allowing stops for snacks and/or toilet breaks.

On the topic of duration, my tip is to actually set the option to "Avoid Tolls" on Google Maps. It will increate the duration a bit, but in the other hand, you will save money from the expensive tolls and most importantly have the change to discover hidden little treasures along the way.

On our trip we used :
- Google Maps : for navigation
- Michi Road Guide : for their offline maps and road stations and onsens list (https://itunes.apple.com/us/app/michi-japan-road-guide-offline/id13810...)

Safe travels