I took our truck in for service at the local Toyota dealer yesterday. When I drove in, I had to drive over one of these big black things:
I figured it was just a speed bump to get drivers to slow down as they entered the service bays. But when I inquired as to their purpose, the answer was more technologically interesting: It's a tire tread depth scanner. As you drive over, lasers shine on each tire, measuring the remaining depth in each tire's tread. Quoting the immortal Dr. Evil … "lasers!"
Of course, when I parked, the technician went around to each tire, sticking his finger in the tread to check the depth. I said, "What about the fancy machines?" 'Oh, they're not quite ready yet; still have to do it the old fashioned way for another few days.' Oh well. Next time.