What apple wants is for people to be able to give more flexible instructions. For maps it could be find me a route from Sydney to Melbourne but by the coast road, and find me a place to stop about halfway there. Or I need to schedule a meeting with Bob next week, find me a day and check with Bob.
Apple wants that?! I wanted that in 2013 and I still don’t know how to do it on the phone! All my mapping is done either on my computer for familiar routes (then I tell the phone landmarks in stages) or AAA triptik.
They haven’t said it, but it is likely that it is part of the plan. If I ask Siri for directions from A to B it will do it, but if I want to add C as part of the route then I haven’t been able to work out how to do it. On a Mac you can add waypoints but it is a bit fiddly. Their aim will be to allow as much as possible to work with a more conversational method.
I went on a forum in 2013 to figure out how to plan a route other than what Maps was giving me. Do you know what people said? “Why would you want to do that? Apple knows the best route, just follow what they say!” Even if it meant bringing me through NYC and over expensive bridges 
It can be told to avoid tolls, but you might not like what it does. A sensible behaviour for it might be to let you know that there was a toll and ask whether you want to find an alternative. Then it could tell someone that they could choose an alternative, it would cost $15 less but would involve an extra 20 minutes driving. The great thing about AI is that people can determine what response the AI should give and then the AI is built to give the responses.
Yes. Avoiding the toll bridges/tunnels crossing the Hudson River is pretty much impossible. You need to drive many hours out of your way.
According to Wikipedia the only toll-free crossings are very far from New York City. The southernmost toll-free crossing is the Dunn Memorial bridge in downtown Albany - three hours north of the City.
I experience this first-hand when coming home from beach trips to Wildwood, NJ. If tolls are permitted, the route home to Virginia usually involves taking the Atlantic City Expressway (toll road) west to the NJ Turnpike (toll road) south to the Delaware Memorial Bridge (toll bridge).
If I tell it to avoid tolls, then it uses county highways west to get to Interstate 295 northbound to get to Trenton, where there is a toll-free Delaware River crossing. Then take Interstate 95 south from there (through Philadelphia). Adding 90-120 minutes to the trip.
Getting navigation over my preferred route (county roads west to I-95 south and pay the toll at the Delaware Memorial bridge) is sometimes (depending on traffic) impossible without setting waypoints along the route.
I’m not sure, however, how you could design a user-friendly way to tell it something like “avoid tolls, except for this one bridge crossing”.
Using the touch interface on iOS, there’s an “Add Stop” button you can click to add waypoints. And thumb-tabs you can use to rearrange the points along the route.
But I’ve never tried doing this with Siri.
My preferred route is to take 84W through NY and then 81. It usually says it’s 10-15 minutes longer but the few times I’ve gone through NYC has proven otherwise.
When I went to the eastern shore (MD/VA) I really had to manipulate it on the desktop and then write down what locations to map by segment. That was the time I got a triptik. I went through the Delaware Water Gap and then headed to the west of Philly and south.
Apple could get some good mapping ideas from Road Trip Planner:
I have been using this Mac app for a few years for touring Australia. It accesses data from Apple Maps, such as trip times, and works wherever Apple Maps works.
I want to be able to plan a train trip in Japan that does not travel via Shinkansen—i.e. using local trains only. It can be a lot less expensive and a lot more scenic that way. But Apple Maps only considers “fast” routes.