How to Jerk and Be a Jerk at the Same Time

You know that part in Drivers Ed where they teach you to ease off the brake as you come to a stop? And if you don't, even though the deceleration of the car remains constant, your passengers feel like they're about to go through the window? Sudden changes in acceleration are called jerk. It's an actual physics term. You feel a jerk because the car was decelerating until it stopped, but once it was stopped, the brakes couldn't make it go any slower. (D'oh.) So the deceleration went from some more or less constant value, to zero, almost instantly. The result: jerk. If you have braced yourself against the deceleration of braking, and then the braking stops abruptly, you are tossed in the opposite direction.

Or, to put it in simpler terms:

Jerk throws things around. It makes them spill. It makes them fall over. When you carry a hot cup of coffee with no lid on it, you move smoothly; otherwise you shower everything in the vicinity with steaming liquid. Coffee is precious. Move smoothly. But as precious as coffee is, I think people are even more precious.

So, now to the point, if you have a bus full of standing passengers, is there a good reason, dear Muni driver, why you can't brake like they are precious cargo? It may be crazy talk but let's pretend, or even presume that drivers realize they are being paid to deliver passengers to their destinations unbruised and right side up.

Most drivers, I think, do. But some, I swear, they are fucking with us. A few mornings ago on the 29, the driver claimed a couple of spry teenagers and a little old lady with her "jerk." She was either lunging forward, lurching while driving (gas on, gas off, gas on, etc.), or braking suddenly as if each stop sign was a complete surprise. All three passengers went down into the arms of other standing passengers, all at different times. I've had rides on N Judah trains with bad brakes (and spaced out drivers) that were smoother.

If you or I drove like that while taking a driving test, we'd flunk before getting out of the parking lot. In that scenario we have one passenger and both of us are belted in behind airbags.

Maybe every morning drivers could take a couple moments to imagine that they're driving a busload of people they give a shit about. They don't have to actually care, of course, but why not pretend.

And this leads up to How to Waste Your Hybrid's Diesel, but that's another post.