I love the concept of moving walkways on large airports and always wondered why there are non with multiple speeds like this one. Is it a security aspect?
There is however an accelerating one at YYZ in Toronto [0].
« Le TRR fonctionna d'abord à la vitesse de 11 km/h (3 m/s), mais en raison de fréquentes chutes de voyageurs et de divers accidents, la vitesse fut réduite à 9 km/h (2,5 m/s) »
From your Wikipedia page, it says it initially went at 11 km/h but was reduced to 9 km/h because of “frequent falls of passengers and various accidents”.
I've walked on the ones at Toronto Pearson before. I was a bit surprised the first time that it wasn't moving at full speed like I expected when I stepped on, but after that the second time I knew what to expect and it worked well.
I actually found it better when disembarking because it gives a better transition to the stationary surface when stepping off.