Thank you for your reports. I will look into the signalling anomalies in due course, but wanted to focus on the performance for the time being. On my computer, running an optimised release build, I get decent performance on the map that you sent, albeit there are slight signs of it working hard (framerate drops for the most part). The UI is responsive.
May I ask what your system specifications are? May I also ask you to check the display settings menu, and give me the output from frame time, idle, FPS and simloops?
For context, my system is a Core i7 950 (the first generation i7), overclocked to just over 4Ghz, and 12Gb of RAM with reasonably decent memory timings.
My frame time fluctuates between 70-80ms, idle is mostly 0ms, FPS is usually 12 (at 4k resolution, but this makes little difference as the graphics portion is multi-threaded these days, as confirmed by my quad-core CPU showing 29% utilisation for the Simutrans executable, meaning that there is consistent load on more than one core) and simloops fluctuates a little, but is usually around 5.0.
I have wondered whether some of the signalling changes have put extra load on the CPU/memory bandwidth, and I may need to look into optimising this somewhat.