I did not do any sort of proper investigation. I just used public transport when overseas when it was appropriate.
We used the the train in Singapore twice, and it works. Perfectly, I would say.
We used The Tube in London, and it works. I can't say it is perfect, as it was way too hot in the odd little train carriages and we had significant pauses mid route, but pretty good. I had to laugh at Tim Fisher, presenter of the ABC's Great Train Show. He said that some of the older tube trains are used above ground in a regional area and that they looked strange above ground and needed to burrow back down to where they belonged.
Although we did not travel on Amsterdam buses or trams, they provided a very frequent service, were not overcrowded and no observed dramas.
Newcastle has an underground overland rail system, called the Metro, like in Paris, and I understand it is very efficient and it is about to have umpteen million pound injected into it for upgrades. The bus service seemed good, with service intervals matched to loading. For security, passenger safety and ticket checking purposes, there was no rear door on the bus. It seemed to not be a problem. Rear exit doors were abolished some time ago on Newcastle buses.
Blackpool trams are not the fastest way to travel, but like all trams, they are very trustworthy. You can see where the rails go and the tram follows the rails. The onboard conductors are a bonus, but then it wasn't exactly cheap. You get what you pay for. There were plenty of buses which I would guess provide a good service and are probably faster than the trams.
Visitors to Melbourne struggle with out public transport ticket system. Locals struggle with it even. But I never had a problem with any public transport ticket system when I was overseas. That tells you nothing about my cleverness; it tells you the ticket systems were easy.
How, when local people overseas scan their cards fast and without any visible to me probems when using public transport, and I assume they do it much cheaper than tourists like us do buying a single trip ticket, do we have to reinvent the wheel? The world over is using stored value scan cards. Why does it have to be reinvented for Melbourne? Why is it so expensive and running years late in its implementation?
The only argument that I have heard that may bear weight, is that our ticket system is very complex........well, simplify it. I despair.