The 15th annual Madison Avenue Derby takes place in Decatur today, October 24. The organizers describe a free-to-watch race for amateur-built, non-motorized soapbox cars. Rather than a static car display, the event puts the engineering on the street: gravity, wheel alignment, steering and the quality of a homemade chassis all become visible when the cars roll.
This is particularly good material for a maker family. Look at how builders solve steering without complex mechanisms, how they position the driver's weight, and how they make their cars recognizable. A few phone photographs of the cleverest chassis details could seed a small 3D-printable project: a steering stop, decorative grille, miniature derby trophy or scale soapbox prototype. You do not need to enter a vehicle to learn from the designs.
The event also raises funds for Decatur Education Foundation, with the race's charitable history reaching more than $300,000 since 2011 according to its organizers. Spectator admission is free. Consult the official site for the day's street route, schedule and parking rather than assuming normal Decatur traffic patterns; a closed street is part of the fun and part of the logistics.
A useful afternoon plan is to walk the course, choose the three smartest design ideas you see, and then take a nearby coffee or lunch break. The attraction is not just watching which car wins. It is watching ordinary people build machines that actually work under the simplest possible propulsion system.