Driving over rail road tracks


#1

Is it better to go over tracks at a faster or slower speed? My wife tends to go over them at a faster speed and it always seems to be smoother than when I cross them at a much slower speed.


#2

It may be smoother when you go over faster…but they are really taxing the shocks/struts and suspension more. Slower is better for the vehicle.


#3

Faster - That way there are only two bumps to experience. (One when you launch into the air, and one more when you land on the other side.)


#4

But that only works if you yell WAAAAAA-HOOOOOOO as you hit the gas doesn’t it?


#5

It greatly depends on the conditions of the crossing. There are some crossings here that are very smooth, with a straight, level crossing at a straight part of the road. I routinely cross this crossing at 55 mph with no fears. I hardly feel a bump.

However, there is another crossing that has a steep grade change, since the road and the tracks are both on curves at the crossing. This one I slow down for because the bump is larger.


#6

Your car’s suspension has a response time. This is the maximum rate of travel that it can achieve. Design plays the most important role in establishing this rate of travel but even subtle differences in equipment or age can alter it so, for the most part, each car is different.

The diameter of the wheel also plays a important role in determining the deflection necessary to bridge the irregularity.

As long as you do not exceed the suspension’s rate of travel, the wheel will always be in contact with the surface. Once you start exceeding this rate, the wheel cannot fully follow the changes in the surface. This is most evident when traveling along a gravel road with washboard ripples in the surface. There is a sweet spot in the suspension travel rate (coupled with wheel size) that will minimize the vibrations transmitted through the car. The wheels are essentially hopping from one top to the next with the minimum amount of suspension travel between them. If you’ve ever experienced this, then likely you know what it’s like when the opposite is true and you hit a bad harmonic frequency and it almost rattles the car apart!

So, it is least harmful to the car (and passengers) to traverse the irregularity at the best speed to minimize suspension travel. The trouble is; the best speed varies from car to car and irregularity to irregularity. Hitting one wrong has the potential to do some serious damage. So it’s best to approach them carefully and go as slow as necessary to avoid a jarring blow. If it’s one you know and go over regularly, you can gauge the best speed for your car. My 2c


#7

It is always better to slow down when you go over railroad tracks.


#8

The Dukes of Hazzard found that faster was best, but they ran through several dozen “Generals” during the prodcution of the series.


#9

If they are the same tracks, look for the smoothest path over the tracks. There is usually one place smoother than the rest.


#10

… And if safe, a diagonal path will generally prove smoother.


#11

Yes, whenever possible, I try to cut a somewhat diagonal path across RR tracks.
That tactic, in addition to looking for the smoothest part of the crossing, will help to avoid suspension damage.


#12

Well, as long as you don’t do what my step-dad has done when I’m in hhis truck on some tracks, one in particular comes to mine. Straight road, fairly smooth tracks, we’ll be doing 55~60mph, then when he’s pretty close to them and slam on the brakes to like 20mph.


#13

This logic makes a lot of sense. The one thing I would add is make sure when you cross the tracks, you are not depressing on the break pedal. This would put added pressure on the breaking system and if your rate of speed is achieved first, you should be ok.