Wikipedia
T-TRAK
T-TRAK is a relatively new modular standard in the hobby of model railroading, which uses modules 2 3/4" (70mm) high, which rest on a table, such as a banquet table. A layout typically consists of four corner modules, each of which has two tracks making ninety degree curves. Straight modules, measuring one or two feet wide are fitted between the corner modules, so that the layout makes a closed loop.
T-Trak is based on a particular track product, namely Kato Unitrack, at least for the interfaces to the adjacent module. Kato Unitrack has joiners which are quick to connect and disconnect to the adjacent track. The tracks are fixed to the base, and the joiners join the modules as well as the track.