The real-time location system would need to track about 10 or 20 go-karts, and would need to be accurate enough to recognize when they drove over pictures painted on the track.
Most active RFID systems are accurate to within about 10 feet, so unless the pictures were large, most systems would not work. You might look into ultra-wideband (UWB) RFID, which can communicate over a wide range of frequencies, enabling the technology to eliminate the effects of waves traveling to a reader antenna via a variety of paths (waves can reflect off materials, making it difficult to determine a tag's distance from a reader). This technology can be accurate to within less than a foot, and might work for your needs.
Another option might be to put tags in the pavement and readers on the go-karts. That way, the readers would pick up the tags as they drove over the pictures. I don't know how fast the go-karts move, or whether there is sufficient time to energize the tag and receive a signal from it, but that might be worth exploring.
—Mark Roberti, Founder and Editor, RFID Journal