I worked on self-driving cars (well, small buses at the time due to the size of computing and sensor equipment of the time) back in 1992 for Daimler-Benz. I was an intern working on the computer vision system (it was a team of 2, including me).
During a test session at an abandoned airfield near Munich, we had my boss's great-grand-boss (3 levels higher) in the bus for a demo lap where we were to follow the car ahead of us at a safe distance and appropriate speed. Our vision system tracked cars frame-to-frame and looked for highly symmetric prominent horizontal lines. We used a pattern of horizontal lines with a trapezoidal overall shape and frame-to-frame consistency as a strong signal of "likely car" and the size of the bottom line (closest to the camera) as the signal for the distance to the car ahead.
The early tests and demos had gone well; we had little tuning work to do while some of the other teams were fiddling with their code and systems for a higher-speed demo after lunch. It had rained lightly in the morning before we arrived, but the sun was coming out and it was turning into a nice day in the late summer. Late summer, warm, sun breaking out meant for drying runway and taxiway conditions.
As the demo started, I was in the back of the bus, seated and belted in front of my rack of equipment and embedded display. Driver, front pax, and two other engineers were belted in their stations, and great-grand-boss was standing between and behind the two front seats to witness the demo. Initially, it was going well and the car we were following was gradually picking up the pace as we drove around the field.
The monitor in front of me showed the live black and white video annotated with output from the horizontal line finding algorithm and distance/closure rate estimates. At around 35-40 kph, I saw my system start to misbehave. As the car accelerated away, the bus was matching the acceleration. All of the sudden, the drying pavement presented a pattern of horizontal lines that our vision system locked onto as a trapezoidal pattern of horizontal lines associated with a car. It had frame-to-frame consistency and so our system decided it was a stopped car ahead and commanded emergency braking. The GGBoss was watching the car accelerate away and the bus matching its pace, so wasn't on guard and I couldn't even shout out an effective warning (as my German was weak and slow to find the words). Bus slams on maximum braking, sending GGBoss forward into the console and dash as the bus groans to a halt. Even after the halt, the "car" pattern on the roadway was still in front of us, so like a recalcitrant horse, the bus refused to move forward until we hit the big red emergency disconnect button and took over manual control to drive back to the paddock area and let the GGB collect himself.
Not my best demo ever...