I was able to do this by using special track that have something called bridgemetalsound on it. The sound is somewhat real and I use it also in tunnels for lack of proper "tunnelsound". Don't have the KUID number on hand now but can look into it. BUT: I haven't been able to find tracks with this feature in T:ane, so the day you up-grade, you will lose it and will have those two white lines instead... Unless someone have a better solution.