The last thing this driver thought would happen is another driver would run into the back of his rear box. We will never know the reason he pulled over, but having a set of triples makes your chances of having an airleak 3X more likely as pulling a single. I've pulled over to the side of the highway many times in my 29 year feeder career. Hell, I've got out at a long light, put my flashers on jiggled a light cord before. Could have been a light issue, might have been losing air pressure on his gauges and had to trace it down. He could have been "watering a dolly." There is no time like the present to nip a problem in the bud. Singles, doubles, triples, it doesn't matter, the profile from the rear is the same for all three. As someone who has seen literally hundreds of sleepy drivers on the highway, I'm speculating here that this was a factor in rear ending a stationary object. R.I.P, brother.