Is Satnav an Aussie term? I only know it from Bluey.
And I use GPS (what we Americans call it, even though that's technically incorrect) for routes I'm well familiar with, mostly because of either traffic awareness or finding a new scenic route.
What it doesn't know is the driving habits of others.
I don't usually drive into work anymore, but my job is in Cambridge MA. For those not familiar with the area, there are two ways in from points south on the highways....tunnel, or pike.
My decision of which way to go comes down to how much traffic I expect at the exit.
If I go Pike, I have to deal with a shitty lane shift at the offramp that nobody executes properly and I always end up nearly getting fender-checked every time.
If I go tunnel, it's like...three consecutive exits that have to be taken. Like you get off the exit, then a sub-exit, then another sub-exit. Between exits one and two you have to get over a lane...except that lane is always backed up past where the first exit merges with it. So you have to be an asshole and speed past all of them and stop somewhere in the middle when you see a good enough gap...or you have to stop at the exit and get in the middle of the line. Either way you have to be a huge asshole to get where you need to go.