This is a continuation of the route testing that GoneNomad is going on the various products. He doesn't yet have Windows 10 and can't test the MAPS app on it. So I've agreed to do a bit for the cause.
I've used his three favorite routes, all starting at 1200 Main St. in Imperial, MO, USA.
First destination is: 1845 Lone Oak Dr, Paducah, KY (or Whitehaven Welcome Center).
Second destination is: 204 Largo Dr, Nashville, TN.
Third destination is: 1530 Collins Ave, Miami Beach, FL.
Each route is a simple A to B route with 1200 Main St in Imperial, MO, always the start point and one of the other three addresses as the destination. No intermediate points because we want to see what the default routing in each product does.
My apologies for the large image sizes that are going to force horizontal scrolling. I could do some compression on them but I didn't want to lose any of the detail. Let me know if it's a big problem and I'll see if I can reduce their size without taking out too much.
When Windows Maps app does the route calculation it typically calculates three or four alternatives for you to choose from. Here's what the first one to Paducah, KY, looks like:
As you can see, the first three alternatives have the same driving time but distances that vary by as much as 55km from the shortest to the longest of the three.
When the route to Nashville, TN, is calculated the first three alternatives have quite similar driving times but the distances again vary by over 50km. One of the alternatives does not go through Paducah, MO. Instead it wanders way south and west. Perhaps it's offered for those who like to take the long way 'round.
When the route to Miami Beach, FL, is calculated, we begin to really see something interesting about how these routing algorithms work. First, only one of the three alternatives offered goes through both Paducah and Nashville. The other two take paths west and south of them.
Although the path through Paducah and Nashville is listed as considerably shorter than the other two - 90km in one and 110km in the other - the other two have been calculated as quite a bit shorter driving times - 1 1/4hrs in one case and over 1 1/2hrs in the other.
So the question becomes, what is the detailed data in the map database telling them? What we can't see is the speed limit data or road closure data. And there may be other data in them that affects the calculation of driving time. Windows Maps even appears to have a Traffic feature if you're connected to the internet but there is no indication whether it is being used in the calculation of the alternatives. When I poked the Traffic icon on the upper bar with the Miami Beach, FL, destination selected, it dropped all but the alternative that had the quickest time on it from the display.
I went back to the Directions page and started that route from scratch to see what happens. The driving times were a little different this time. Is it possible that Maps is automatically factoring in information it's seeing from the traffic cameras along the way? I'm not sure how I would tell for sure.
What I do know from experience is that most of the routing algorithms will default to the Quickest Time. You normally have to force an override to get Shortest Distance, if the product even has that feature. I cannot find such an option anywhere in Windows Maps. But the way it offers alternative routes that clearly cover a variety of factors, I'm not sure it matters. It offers the driving distance for each alternative, as well as the driving time, so I can choose whichever one I wish.