The empty highway stretches straight out to the horizon, so I take a moment to peek at the electronic display down in the car’s center console. I read out the numbers on the screen swiftly and glance back to the windshield, when I see ... nothing. A dense fog has swallowed the roadway, and I am driving blind. Before I can feel for the foot brake, an unmistakable warning—a brake-light red rectangle—flashes onto the windshield. Without another thought, I slam hard on the pedal, cursing loudly. My vehicle comes to a hasty halt as a disabled car emerges abruptly from the murk dead ahead.