On the very first tram ride carrying invited members of the public, the calmest passenger was Mr Wiley.
There he sat with his companion, Jo Weir, utterly unmoved by the crowd pushing around him. Occasionally, he raised an eye-brow but only minimally, maybe in disapproval of the media and politicians' scrum.
But mostly, he sat it out quietly for the journey from Gunghalin to Civic.
And that's the way it's meant to be for a lovely black Labrador helping his human companion negotiate the new system.
Ms Weir has been with Mr Wiley for just under eight years. The two took the first tram on Thursday, reserved for dignitaries and the winners of a lottery.
Ms Weir was impressed with the way the system has been organised for people like her who have impaired sight.
"I have actually trained Wiley (she is sometimes less formal with him and drops the Mr) to find the boarding point for the light rail vehicle," she said (eschewing the word "tram").
"In this particular platform, I know that it lines up with the seating area so once we're at the seating area I know that that's my entrance into the light rail vehicle."
She liked the "Tactile Ground Surface" indicators on the platform - the raised bubbles that signal the edge.
Once the train arrives, Wiley leads her into the carriage. She instructs him to find a seat and he leads her to an empty seat reserved for people who might need it.
There is then a lot of "Well done, Wiley".
Mr Wiley has been trained to find what Ms Weir calls destinations. They can be general like a door or specific like a particular station or bus stop or shop.
Or even a Target store. This training involves a process of instructions - "Find Target", for example - and then leading the dog there and rewarding him at the end. After repeated attempts, Mr Wiley knows the way.
The rewards are gradually withdrawn as Mr Wiley learns. He likes a bit of liver but will also take a carrot. "He's a Labrador. Food is food," said his human companion.
The affection never ends, though. The human continually praises the canine. "Well done, Wiley!"
"It is absolute teamwork'" Ms Weir said. "That's the lovely thing about the guide dog relationship. I need him and he needs me."
At the Gunghalin tram terminus, she knows the layout in her mind so when Mr Wiley finds a general area, she knows where seats are and where the train door is likely to be. Mr Wiley also knows where the priority seats are in the carriage and can spot an empty one.
She offers advice to the public: offer assistance but don't assume that somebody needs it; vacate a priority seat if someone needs it.
At the end of the ride, Ms Weir had nothing but praise.
"It's really nice that Wiley and I were invited on this trip because it shows a great understanding of the public access rights that a handler has to take their dog on all forms of public transport, and that public access also includes all public places, including restaurants and cafes and hospitals."
And don't pat the dog - it distracts him. "They're actually working really hard and if you distract them, they are not going to be focusing on their really important job," said the handler.
On the light rail system itself, she liked the level entry into the vehicle, the announcements, including which side the doors would open, and that the priority seating was right next to the door "so you can get your seat nice and quickly".
And one thing she really likes about the tram: it only goes in two directions.
"I have on a number of occasions got on the wrong bus and ended up somewhere where I didn't want to be. At least with a light rail vehicle, you know you are getting on the right one. That makes life easier."
Mr Wiley declined to comment.