Alexander,
Just a heads-up... The crossover section of your layout basically has 3 quarters of a turn to elevate the track to clear the underpass. That means with an 18"-radius curve, you got 18 x 2 x 3.14 x .75 = 85 inches of horizontal travel to elevate the track.
To clear the underpass (accounting for the roadbed and the deck thickness of the bridge overpass), you need to elevate the crossover by at least 3.5 inches. 3.5 / 85 = .041 x 100% = 4.1% grade. That is very, very steep, and when you figure in the rolling resistance due to the very sharp curve, I think most HO engines out there will have trouble pulling even a short train of less than 10 cars up that incline.
You might want to think about making the crossover loop with a wider radius to make the grade less severe. For instance, if you use a 22" radius curve, you get 22 x 2 x 3.14 x .75 = 103 inches of horizontal travel to elevate. 3.5" elevation will work out to a bit less than 3.5% grade, with an easier curve. It's still very steep, but at least your engines should have a somewhat easier time pulling a train up that incline.
Food for thought! :thumb: