if there is a requirement for Rail Replacement to be compliant then the law courts should be having a field day prosecuting all the bus and rail companies involved as many non- compliant vehicles turn up on rail replacement.
The fact that a law is not enforced, or that it is widely ignored, does not necessarily mean that the law doesn't apply. It just means the law is widely ignored, often to the point that the people providing the service are unaware of the law.
An analogous example:
The Public Service Vehicle Conduct Regulations make it illegal for a bus driver to refuse to operate a ramp or to refuse a wheelchair user access to an unoccupied wheelchair space; and "unoccupied" is inclusive of situations in which passengers or their effects are in the space but can easily and reasonably move. Any driver failing to comply with this regulation faces punishment on summary conviction by a fine not exceeding Level 3 on the standard scale, and endorsement of their licence. This has been the case since 2002.
Yet no driver has ever had any legal action taken against them under this legislation. There is no body tasked with enforcing this legislation.
The fact that it hasn't been enforced does not mean that the legislation doesn't apply, it just means it hasn't been enforced. Such lack of compliance can become deeply ingrained and accepted as standard practice. The DVSA and the DFT are currently making formal enquiries of National Express and Megabus/Scottish Citylink after I revealed that both were refusing wheelchair users spontaneous access to unoccupied wheelchair spaces because they claimed they needed advance notice to prepare the space. Both have had a "36 hour notice" requirement for years, but are now being forced to change to correct their failure to comply with this legal retirement.
So with respect, and I genuinely mean that (I should imagine arranging and supervising rail replacement transport is a.major headache), the fact that you are under the impression that PSVAR doesn't apply to rail replacement vehicles, and you perform your job based upon this understanding, does not validate your assertion that PSVAR doesn't apply.
The fact is that, unless you have authority from the rail company to travel on the vehicle {ie you possess a rail ticket} you are not allowed travel on a rail replacement bus/ coach. It is a closed contract vehicle at law, in the same way as many school contracts are, as are private hires, as are
coach holidays.
You are incorrect in your assertion.
In actuality, if access was free without any rail ticket, then PSVAR would not apply. It is required that somebody pay somebody something in respect of each individual's right to be on that bus. It doesn't matter who pays, or to whom (it doesn't have to be the passenger, or the bus operator, or the train operating company), or even if the payment takes into account other things in addition to transport on that bus. As long as somebody has made a payment to somebody that includes at least in part the right of a passenger to travel on that bus, and that bus runs to a schedule, then PSVAR applies.
Private hire and coach holidays are different. So are school buses that are funded fully and exclusively by the local authority, but if any one passenger on that bus has had any payment made to anybody for their right to travel on it, the accessibility obligations kick in. This is why there are now examples of local authorities refusing to allow pupils or parents to pay the local authority or bus operator to travel in a spare seat on such buses: because the bus would then be subject to the PSVAR and would have to be accessible (and accessible buses are more scarce or more expensive.)
The collorary is: complimentary / free buses are not subject to the accessibility requirements. So complimentary buses to the supermarket, free city buses as used to run round Leeds city centre, and so on, are not subject to the PSVAR and are not required to be accessible - except for if they're "complimentary" to an event and tickets for the event are required in order to board them, in which case the cost of access to the transport is considered to be part of the event ticket.
A challenge: Show me where the PSVAR 2000 or Equality Act 2010 state that services under a "closed contract" are not classed as scheduled services and are thus exempt from the requirements.
Your reference to "scheduled public services" is incorrect by the way - a service doesn't have to be public before it is subject to the PSVAR. For example, school buses for which local authorities allow school pupils not entitled to free school transport, to use the bus on payment of a fee to the LA,, are subject to the PSVAR. Yet anybody who wasn't a school child at the relevant school, or hadn't paid the local authority for the right to travel on that bus, would legitimately be refused access to that bus.
The fact that a rail replacement bus isn't open to the general public, and that a rail ticket must be bought to entitle one access to the vehicle, in no way obviates liability under the PSVAR.