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Definitely don’t care about that. The guy behind me can worry about himself and keeping a safe distance.
What is a safe speed since you mention there being a safe speed to go over railroad tracks?
Also, do you get outside of your 4Runner and measure railroad tracks to see if they’re less or more than 3 inches before going over them?
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If you're slowing to 1mph to cross the tracks, you might as well stop on the tracks and measure 3"! (That's what she said!)
I never mentioned safe, I said appropriate. I've crossed railroad tracks at 75mph, and others I've creeped over at 5mph. It's what is appropriate to the conditions, which are often defined by the speed of the idiot in front of you.
WARNING: SCIENCE/NERD ALERT
Simplified, the suspension movement is with the physics of
simple harmonic oscillators and
interference waves. In this case destructive interference is your goal, the smoothest ride, created by the harmonic return of your spring (suspension) out of phase with the wave of the ground form (railroad crossing). The issue is that the crossing is significantly less than ideal, flat waveform, and is often irregular. So while a speed X might produce a flat waveform at the first several bumps, that same speed might provide constructive interference on the 2nd set of tracks. Hence your desired speed should be the one that produces the flattest waveform, or smallest deflection of your mass (wheel assembly) on your spring (suspension). By reducing to the minimum speed, you're attempting to ride the waveform up and down, actually creating a situation of constructive interference. Which is why the bumps feel much more significant at slower speeds.
Can you do the math on every railroad crossing on your daily commute? Sure. But who has time for stuff like that, and with CommonCore you'd probably lose your job before you found an answer. The best advice, learn the tracks you drive on a regular basis. Approach them at varying speeds and see which provides the smoothest ride. It could be the speed limit, 10 over speed limit, 7mph, 34mph, you won't know until you try. While the unsprung mass changes very slowly (weight of wheel assembly) the weight of the vehicle may change on a daily basis, fuel level, passengers, cargo, gear, etc. That determines the amount of force already on the springs, and hence their ability to absorb more force along the waveform.
Though Luke & Bo preferred the physics of ballistic arcs, thereby negating the interference from the crossing, as demonstrated by acceleration over an inclined plane.
