It's more of a shame that the amount of people trying to use this angle as a scam is bigger now than ever before. I've run a comparable ticket office for 5 years now & have always dealt with the enquiry for a carers ticket on trust. In the last 2 years, we've seen so many of these free tickets finding their way on eBay, to be sold on at higher than face value!! Unfortunately this has meant we've had to introduce the need to ask for DLA or similar in order to try & stop this happening. So I blame these people that have forced our arm to react unfortunately.
I can see that. Our season ticket is ambulant disabled and companion as my other half is visually impaired. We had to produce the dla letter at point of purchase, it's not a big problem but sad that it's a system that people have abused over time in enough numbers to make it necessary to check.