A website which is for track safety companies. Its employees can use the website as well as the app (linked on the website) to find out about current training courses and exam questions with exam answers. Safety Supervisors (SA), Safety Instructors (SIPO), Helpers in Railway Operations (HiB), Switching Applicants (SAS Switch off overhead line) exam questions and answers. You can also study normally with the Deutsche Bahn signals. Learn more: https://signalbuch.org/