TPWS is not a replacement for AWS. It's supplementary to it. They are different systems. The primary purpose of AWS is to try to reduce drivers missing distant signals (or for colour light signals, missing a single yellow or double yellow aspect).
The primary purpose of TPWS is to try and reduce the risk of collision (or the amount of damage if a collision does occur) if a train passes a fitted signal at red.
As others have said, TPWS is only fitted to a relatively small number of signals (normally those where there is a point of conflict ahead of the signal, such as points / junction or where other risk factors apply in the determination of the decision to fit it).
Attending and fixing AWS faults should be no different in priority to what it was in the past. The priority had not been changed when I led an S&T faulting and maintenance team back in 2023. As long as there were no train stopping or train delaying faults, we attended AWS faults as soon as we could. If the fault came in during my shift, we normally were on site within one hour. Depending on what we found, rectification could be within one hour, 24 hours or in some cases, the work would require planning at a weekend or night turn (due to a lack of access, because only then could a suitable line block or T3 worksite be obtained). If we were out of spare units, it sometimes took weeks, sometimes a couple of months though, that's because there was a lack of suppressors).
