Modify a route in Apple Maps?

I'm leaving on a 500 mile road trip tomorrow and figured I'd give my iPhone 5 a try at handling the navigation. I've been to the same destination twice before, most recently August of last year, so I know how to get there most of the way except the last 100 miles or so.

When I select the start and end points in Apple maps, it gives me 3 route choices. One of them is close to the route I took last year, but it's not the shortest route. Maps reports it as 491 miles.

If I switch over to Google Maps and enter the same start and end points, it DOES give me the choice of the route I took last year, and it reports that route as 484 miles. The routes are the same except the last 50 miles or so, and the route I want to take (shown in Google Maps) is 7 miles shorter.

I'd rather use Apple Maps because I don't have to keep the phone screen on all the time, and when the screen comes on for a turn notification, it shows the map and my location progress in the lock screen. Google Maps only shows a notification in the middle of the screen with my normal lock screen wallpaper.

So really I just need to move a short portion of the route in Apple maps over to a nearby road for the last part of the trip. Is there any way at all to make this happen?