Design News for Mechanical and Design Engineers

I, however, have come up with a solution that works. Post speed limits in metric units. I proved it recently while driving across Morocco. There speed limits are posted in kilometers, just like virtually everywhere else on the planet except the U.S. and the U.K., where at least they have a better excuse!

During a cross-country trek, I tore my eyes away from the exotic sights long enough to realize that our rental car—with my lead-footed husband at the wheel—was not exactly hustling along. I'm not sure what the maximum land speed of a donkey is, but I'm positive a few of them passed us on the road to Marrakech.

Notwithstanding the fact that our Fiat began to shake violently at about 100 km/hour, I was curious. Why did this speed demon seated next to me have no compulsion whatsoever to drive the 120 km/hour speed limit, much less exceed it? His answer: "It doesn't make any sense, but when the needle on the speedometer hits triple digits, I feel like I'm going really fast."

Can this kind of psychological governor work on all speeders? One shortcoming of using the metric system is that it will probably only be effective on people who have to do the conversion in their heads—in other words, every U.S. citizen currently holding a valid driver's license.

But perhaps we need to consider a different system of units. A speed limit of 65 miles/hour in Base 8 (101) would meet the 3-digit psychological thresh hold. So would Roman numerals (LXV), which would be a heck of a lot more interesting. But, hey, what about Binary (1000001)? Just trying to keep track of all those digits would make us all forget we were in a hurry to get somewhere!