A record of 1205 cars and 26 locomotives was set by a 2-rail modeler in 2010 Chi-Town Union Station in Metro Detroit.
"Chi-Town Union Station is also the home of the world’s longest model train.
On March 20, 2010, Chi-town assembled and ran on a permanent indoor model railroad layout, with grades and curves, a train 1,112.06 feet in length consisting of 1205 cars and 26 locomotives. The train weighed almost 1400 pounds."