When we travel, and we do it this way this a lot, we run Street Atlas underway. With a GPS attachd, and the day's plan in front of the navigator, there are a lot of problems that can be avoided before they are any inconvenience.
We actually run at least two GPS and sometimes three at the same time. This may sound a little paranoid, but it really is not. It has proven to be advantageous on more than a few occasions. The Garmin is supposed to be up to date and it has a traffic receiver. But, there is a lot of this country that has no traffic service.
Before departure, we will load the little GPS (A Garmin 2595LMT now) with the days expected route. This will include any stops already planned. As the little unit is not good at understanding what we really want, this can be tough.
But, the navigator (usually me - DW likes driving) will have the real plan on the laptop with GPS and Street Atlas. Street Atlas gives the navigator a good estimate of where a fuel stop should be and helps to give a good idea where to plan End of Day. If the navigator updates the route with the changes, Fuel and EOD get updated as well.
An Android phone is the last piece. The phone provides both a continually updated traffic data, so I can load a Google maps route and see if that agrees with the other two. This allows the navigator to re-route before it is an issue. It also provides a hotspot to allow us to search the area for other items of interest. We have found more than a few that were not in the guide books.
And all this works underway and takes so much stress out of traveling that it is a joy.
Matt