For those curious about the making of Off-Road Algebra, this article about “authentic scenarios to teach abstract concepts” has a section on how it went down.
Dyer focused the videos on algebraic principals that exist naturally in motocross, such as the formula for velocity. “‘Velocity equals distance divided by time’ is a fundamental formula for any kind of motion,” he explains. “The ramifications of it go all the way through calculus, yet it’s also essential to motocross. I could have done the entire series just on that principal as it applies to racing.”
It also has a good rundown of efforts at other schools.