There is a hidden setting in Railworks, that will allow you a quick test run for your scenarios. The trains will be driven by the AI, and you can speed up the time to see if everything works as intended. It does not substitute a real player driven test, especially for freight scenarios with (un-)coupling instructions, but a good and quick way to check them.
You have to add the start parameter -followaitrain to RW. If you have made a desktop shortcut to RW right click on it, go into the properties and add it behind the Steam.exe -applaunch, should look like this in the end (or wherever Steam is installed):
"C:\Program Files\Steam\Steam.exe" -applaunch 24010 -followaitrain
Alternatively add it directly in Steam, right click on RW in your games library, select properties and then the button "start options" on the first tab, just add the -followaitrain there.
When you load up a scenario and hold [ctrl] while you left click on a train/loco and the AI will drive it for you through all instructions and you can just enjoy the landscape. You won't have access to the standard passengerview but you can adjust the camera position to go inside the wagons. With [PageUp] and [PageDown] you can swith between the trains.
Also: when you enable the checkbox "EnableAsyncKeys" in the RW launcher you can speed up the time through pressing [shift-ctrl] +  up to  (1 normal speed, 2 double, 5 is 5x speed). Beware that this will prevent third-party locomotives that use these key-presses for other purposes from working correctly.