There is a way to make levers that properly function. Sputnik did this on many of his rail cars. It may be possible to make working switches out of this concept, maybe even buttons with slide nodes and shocks, but there is no way to make buttons clickable in the same way buttons are clickable in...
There are a few questions that need to be answered before this one;
-What version of RoR are you using?
-What are the vehicles that are causing the crash?
Also, post your ror.log.
Keep in mind that support for 0.4.7.0 has been dropped, so upgrading to 0.4.8.0 most likely is your solution.