Follow
Agreed that it's hard to measure value of interventions in an adversarial situation (because their existence changes the adversary's behaviour). Given that TfW apparently also has conductors I don't see how the additional deterrence would be significant.
BTW for context, it seems that TfW is getting ~120Mpounds per year from tickets out of ~700Mpounds of revenue (which include some non-passenger services and mainly grants from various levels of government). Source: grep for "revenue from contracts" in https://tfw.wales/sites/default/files/2024-07/TfW-Annual-Review-24_ENG.pdf
