How to let the automata of ELrail tram and monorail train won't stop when through the overpass lot?
I guess you can't change that behavior. Maxis programmed the el-rail and monorail automata in a way that it stops when passing through a transit enabled lot - being an actual station or not. For some reason, they didn't do the same with the regular rail, though, so even at TE'd railway stations, train automata won't stop.
I think so ....
It seems not good idea that use lots to enhance traffic system...
You are right about that. The original purpose of the Transit Switch properties is to provide the sims with a place where they can switch to another form of transportation, but when the idea of el-rail and monorail came up when Maxis developed Rush Hour, I guess they simply hard-coded the automata stop into the game, not considering that transit enabled lots might be useful for other transit types as well. Later, they made the large railway station and the tollbooths, but didn't add the stop feature to those for some reason. After the release, people started to see other interesting usages for the TE lots, but I guess they were never intended for just letting automata through the lot without an impact on the traffic simulator.
well, forget it!
it's time to watch《24:Redemption》 ;D