That was then, When was now possible?

Last week at the Red River Valley Sugar Beet Institute Expo, I got involved in a conversation about Slow-N-Tell with an older gentleman who really did not think that the lack of visible brake lights on trucks when slowing down was much of a big deal. His point was that when he was young, everybody just stayed back from the trucks because they smelled badly of unburned fuel and usually belched large clouds of black smoke when the driver downshifted to slow down, so you kind of used the smoke like brake lights.

It was an entertaining conversation, not the least bit confrontational, but once we discussed today's more fuel efficient trucks, efficiency of Jake brakes and huge difference in truck engine technology between then and now, he came up with an interesting question. Here it is, paraphrased. "When did truck technology evolve to the point where this product could have been designed?"

While I am not certain of the first truck to use a hall effect speed sensor (transducer) to send a frequency signal to the speedometer or even when it occurred, I do know that this important piece of technology was the breakthrough. (Feel free, please, to let me know when it occurred and on what equipment it was first used, if you know.) Prior to this technology, a gear drove a cable that ran into the back of the speedometer. There would really have been no way to capture a signal that could have been run through a computer module to calculate the deceleration values that we use to illuminate the brake lights. Then again, there weren't even onboard computers in cars, let alone trucks, until the latter 1980's with the advent of the OBD (On Board Diagnostics) systems that monitored little more than fuel injection systems.

Once trucks started using the speed transducers, the technology was in place to allow illumination of brake lights on heavy trucks. Why didn't someone do it until now? I am not sure, but let's leave that for tomorrow's conversation.