I have drawn some new signals looking similar to those found on German railroad tracks.
For explanation of German signal system see http://www.sh1.org/eisenbahn/shhp.htm
UPDATE: Version 0.4
+ new pre signal graphics => no more unrealistic waiting at distant (VR) signals
+ changed exit signal post plate to white-red-white
+ better post plates for PBS
+ one-way PBS now has ground-level blocking signal on it's back
UPDATE: Version 0.3
+ PBS support
Screenshot: