Put track breaks on audio CD

I listen to instruction speakers on a CD while I am driving the car. My job has changed somewhat so that I am in and out of the car between clients with about 20 to 40 minutes driving time between visits.
Does anybody know how to put breaks in an audio CD similar to the track breaks on a music CD? What kind of free software do I need and how to do it?

WinAVI can do that I'm sure. Just convert to mp3 and in options should be an option to split at certain intervals. Or just google mp3 track splitter...