I had some problems with some S curves on my layout. My Dash 9’s had a little trouble negotiating the curves, especially when running freight cars behind them. The wheels would sometimes come off the track. So today I removed 3-4 curves and put in straights which seemed to improve it immensely!!! Here are a series of three pictures to show the before and the after. The Regal
This is before
These last two are after.
This one I had to remove one more piece to accomplish what I was going for.