As title mentioned, There are only few sizes of railway sign can be used. Also, No single Sign can be used.

Thus, I suggest the railway sign can be modified as the lift system, which providing options that we can adjust the sign what we need.

In addition, there are some cases that signs are sticked together but seperated as the image following.

To Implement this effect, displacement is main point. I advise in the sign adjustment panel, not only changing the sign content but also can split the sign into two or more parts in appearance.