The topic of Peter, Jimmy, and Sheila's project is Transportation.
For the project, the small committee of three has to come up with a poster and a booklet, plus an oral presentation on the topic. The three classmates decide that the boys will work on the poster while Sheila will concentrate on the booklet. At the library, they borrow seven books on transportation so that they can learn about 'speed, traffic congestion, and pollution.'
Meanwhile, Peter proposes that all traffic should be prohibited so that air pollution will cease to be a problem; he thinks that they should write about the monorail system, which he believes will effectively solve the problem of air pollution. Sheila disagrees, because she thinks it is too expensive to build a city-wide monorail system. Furthermore, she reasons that they will never find enough information about the monorail system to fill up twenty pages for a report.
The two boys argue that Sheila is far too bossy; in the end, the boys work together to complete their poster, and Sheila works on the booklet, as originally planned. A comical exchange occurs when Sheila accuses Peter of drawing a truck which looks like a flying train. Peter assures her that his truck will look like one when he's done with the poster. In the end, Peter, Jimmy, and Sheila's committee is the first committee to give its report. Despite being pleased with their work, Mrs. Haver, their teacher, questions why the kids included a picture of a flying train on their poster.