1. PURPOSE

The purpose of this rule is to outline the protocols for Authorising and using Absolute
Signal Blocking (ASB) in the Public Transport Authority (PTA) Network. This is a
method of working in the Danger Zone by:
 maintaining Controlled Absolute Signals at Stop to exclude Rail Traffic from the
limits of a Worksite; and/or,
 where the Signal has more than one Route available apply Blocking Facilities to
protect all entry points to the Worksite.