Margery Cuyler is the author of many books for children, including The Little Dump Truck, The Little School Bus, The Little Fire Truck, and That’s Good! That’s Bad!The idea for That’s Good! That’s Bad! was inspired by a conversation with her young son, Thomas, who asked, "Can't bad things change into good things?" The vehicle series was inspired by both her young sons who never tired of playing with cars, trucks, and trains. Margery Cuyler's children have since grown up, so these days much of her inspiration comes from the children she meets on school visits. She and her husband recently moved to Lawrenceville, N.J.

Bob Kolar has written and illustrated several picture books, including AlphaOops, Racer Dogs, and Hello, Fire Truck. He lives in Lee’s Summit, Missouri, with his family.