Road trip / Jim and Gary Paulsen.

Enhanced descriptions from Syndetics:

A summer adventure you'll never forget, from a beloved Newbery Honor winning author!

Dad and Ben haven't been getting along lately, and Dad hopes a road trip to rescue a border collie will help them reconnect. But Ben is on to Dad's scheme, and he's got ideas of his own. Like inviting his buddy, Theo, who's sure to get into fun (and trouble) along the way. And if Dad wants a family road trip, then the family dog, Atticus, should get to come, too. What could go wrong?

But when their truck breaks down, the family trip takes plenty of unexpected turns. Before they know it, they've commandeered an old school bus and joined forces with its cranky mechanic, Gus. Next, they pick up Mia, a waitress escaping a tense situation. Only sharp-eyed Atticus realizes that Theo is on the run from something bad--and someone is following them.

With alternating chapters from both Ben and his dog, Atticus, this fast-paced book takes readers on an unpredictable ride that's all about family, friendship, and surprises.