The tape makes a nice trip souvenir. The type will vary with the skills of the children. Take along a collection of family stories for long stretches of highway. Stories that relate to the area are nice. But family stories need not be old to be interesting.
Parents can tell about their childhood, courtship, wedding day, or other events.
Various games can be played by spotting license plates. The first one to spot the next letter gets one point. Score two points per double, three per triple. Write down scrambled names of places along your route and see who can unscramble them first. Or see who can make the most words from the name of a city or river.