I've always been curious about the way things work. When I was five years old my Dad brought home a new-fangled transistor radio and I had it dismantled in no time flat. The fact that I was able to reassemble the parts into a recognizable and working radio was not the result of mechanical aptitude as much as it was from fear of Dad's leather belt. It had been the same with my first bicycle and with most other things that could be taken apart for examination. It was not, however, through my own investigation that I discovered the Brain in the Stainless Steel Box.

When I was learning to drive a car there were city planners and civil engineers across the country scratching their collective head over a way to more effectively move traffic through cities that were growing at an alarming rate. Traffic lights, for example, were on set timers; law-abiding motorists often sat at red signals for several minutes while cross streets for which the signals were green were free of any traffic. By the late nineteen seventies several solutions to the traffic flow problem had been proposed. In nineteen seventy-eight one such plan was adopted and implemented nationwide, but was never announced to the public. It may well have become obsolete without most people ever having learned of its existence.

My friend Kathy invented the system of pressure sensitive pads that over-ride timers to trigger changes in signal lights. Kathy's a certified genius; a member of Mensa, an alumni of Boston's Trinity College and was the first woman in the U.S. to become a Certified Data Processor (more years ago than she cares to admit). Kathy explained to me how the network of pressure switches works long before it was ever implemented.

Although a few intersections here and there are still on timers alone, even casual observers will notice a rectangular pattern of incisions in the pavement at most signal lights that mark the pads themselves. They are most noticeable on concrete and are all but invisible under asphalt. On concrete all four pads can be seen to be connected via linear incisions in the roadway to a stainless steel box about four feet high; the brain of the system. When a signal is red, the weight of two "average" vehicles will trigger a change in most lights within five seconds. Busier intersections have longer pads that require three or four vehicles' weight. The pads almost always extend to the very edge of an intersection or crosswalk. It is the combination of placement and pressure setting that has made the system largely ineffective.

For one thing, today's "average" vehicle weighs almost a full ton less than the big boats people drove two decades ago. Without sufficient weight on the pads, the "brain" reverts to its archaic timing mechanism. More significantly, polite drivers stop at a respectable distance from crosswalks, which prevents a second car from lending its weight to the pressure sensitive pad. I have tried to help the system to move traffic along by always pulling to the end of the pad, only to watch the cars behind me and in the other lanes stop more than a full car length behind me. I have pulled up onto the rear end of a pad when doing so meant almost touching bumpers with the car ahead of me. Unaware of the presence of the pressure sensitive pads, many drivers with whom I share the road have misinterpreted this practice as some sort of threat and reacted with obscene shouts and gestures. My consolation is that I don't have to remain to listen to their abusive verbiage for much more than five seconds.

The failure of city planners to publicize the existence and function of the pads is the reason for four and five block backups of traffic at signal lights that remain on timers when they could easily be triggered to change almost instantly. Once, in a left-turn lane, I sat behind a driver that was stopped so far back from the intersection that neither their car nor mine was on the pad at all. Pads in left turn lanes are often set to skip the signal for that lane when no pressure is sensed. All of the othe lanes of traffic around us cycled through three changes of the signal light without our lane ever receiving a green arrow. Finally, I got out of my car and went up to the driver ahead of me, tapped on their window and said, "If you pull up ten feet, the light will change in five seconds and we can get out of here." They did. It did. We did. I imagine they think it was some sort of magic.

Try the pads yourself. Work with them. Play with them. Sometimes you can fool them. Late at night, when there isn't much traffic, I'll pull up to the front edge of a pad and shift into reverse. When I've backed to the rear edge of the pad I go forward again. Sometimes the rocking motion will trick the brain in the stainless steel box into believing that there are two cars on the pad. I count down five seconds aloud; five Mississippi, four Mississippi, three Mississippi, two Mississippi, one Mississippi, Go! It almost always works. Whenever it does I smile to myself with the satisfaction of a secret knowledge as I drive away from the signal. Easily amused, aren't I?