I’m surprised that you are treated in this way Roger as I am able to have my annual check done at the closest hospital to my home which is near a bus route.
I don’t use my car as they tell you not to drive after the scan as they are aware of the effects that it has on your vision for some hours afterwards.
To expect you to struggle there and back home is not on and I would suggest that it is worth raising this at your next diabetes clinic check.
Also it may be worth raising or researching this question on this diabetes forum which provides a lot of useful information.
https://www.diabetes.co.uk/