Each track has its own sensor looking down on the track to detect the train
Each track also has an input for external control
Jumper selectable short (4 or 10 second) delays
between stop / caution and caution / clear or go
Strong ABS plastic construction with stainless steel ladder
Fully assembled and tested
As always: just set it & connect it - your done! 
Can be upgraded with additional tracks and/or signal heads.