[TRR] is a [French] acronym for "Trottoir Roulant Rapide", the new high-speed moving walkway or [travelator] currently being tested at [Paris]' [Montparnasse] station. In October the [metro]'s safety committee will decide of the invention's fate.

Like many of the bigger stations in [Paris], many different train lines pass through [Montparnasse]. While this is convenient, it does mean that one can walk quite a way when changing trains. This is by no means a unique problem. At the [Charles de Gaulle] airport, [TGV], 2 [RER] lines and of course the [airport] all come together but you need to be prepared to walk. Ditto [Gare du Nord] which connects many main line trains, [Eurostar] , [Thalys] and 2 [RER] lines. [Chatelet] deserves to be mentioned, although it only connects metro and [RER] lines, some journeys involve more time walking around [Chatelet] than in the train. Similar situation can be found in stations and airports around the world.

[Escalator]s and moving walkways are in widespread use, while they make the journey a little easier, they don't move that fast (usually around 3km/h). The TRR by contrast moves at 9km/h and could move as fast as 11 km/h.

You can't just dump people onto something moving that fast, people would invariably fall over. The TRR is split up into 3 parts:

The first one moves at 2.2 km/h (similar to the speed of a normal moving walkway) and is a moving belt of [roller]s. At the end of this stage a smooth metal plate allows users to slide onto the next stage.
The middle (and longest) section is the actual high-speed section, apart from this it is similar to a traditional moving walkway.
The last section is similar to the first except that it is designed to decelerate people instead of accelerating them.

Prominent signs at the 2 transition points tell people to keep their feet flat on the ground and to hold on to the handrails, it's not difficult to see that otherwise people risk landing flat on their face or on their backs.

Everyday there are new users, so accidents do happen. Old hands ignore the warning signs, newcomers copying them occasionally fall over, sometimes hurting themselves In a small number of cases compensation has been paid to users.

Reactions from users have been mixed. Some are scared, overjoyed at still being alive when they reach the end and promptly swearing never to use it again. Some of the younger users feel it's not fast enough. Other regular users feel that it is a great timesaver, calling it the [TGV] (Trottoir à Grande Vitesse). Overall similar reactions to the first [escalator], it takes time for people to get used to new things.

It has attracted a lot of interest from experts around the world, but it may not be for everyone as the TRR does need a flat, straight, site. It isn't recomended for [walking stick] or [zimmerframe] users either.

Sources:
http://news.bbc.co.uk/1/hi/world/europe/3001182.stm

TRR (thing)