Field note. The metal shells have stopped breeding forward motion.
Each shell contains one human, sometimes two, sealed in climate-controlled solitude. They have arranged themselves nose to tail across a river of pavement wide enough for a herd, and now they do not move. The engines continue to burn fuel. The shells continue to consume the world in order to travel no distance at all. This is not a malfunction of the machines. Every machine functions. The malfunction is systemic and self-inflicted.
Observed behaviors during immobility: the human strikes the round grip in the center of the shell, producing a blast of sound that changes nothing. Another human, four shells ahead, produces an answering blast. They cannot reach one another. They cannot help one another. They emit the sound purely to broadcast displeasure into a void that does not receive complaints. I have logged this as a distress call with no intended recipient.
Further note. The face of the human at rest in the stopped shell displays elevated jaw tension, rapid ocular flicking toward a small reflective panel, and repeated glances at a wrist device measuring a resource they call "time," which appears to be leaking from them at a rate they find unbearable, though I can detect no wound.
They built these shells to move faster than their own legs. They built roads to carry many shells at once. They then acquired shells in such number that the shells now imprison one another, and each human sits alone inside its faster-than-walking device, walking speed unattainable, screaming a horn no one can answer.
They call the ability to travel freely "freedom." They have purchased so much of it that none of them can move.