Track geometry car

Some of the parameters generally measured include position, curvature, alignment of the track, smoothness, and the crosslevel of the two rails.

Track geometry cars emerged in the 1920s when rail traffic became sufficiently dense that manual and visual inspections were no longer practical.

By 1927 the Atchison, Topeka and Santa Fe Railway had a track car in operation followed by the Estrada de Ferro Central do Brasil in 1929.

Southern Pacific's GC-1 (built by Plasser American) was among the first and utilized twelve measuring wheels in conjunction with strain gauges, computers, and spreadsheets to give managers a clear picture of the condition of the railroad.

More commonly, on freight railroads, geometry cars travel at track speed (up to 70 miles per hour) to minimize service disruptions.

Current track geometry cars may cover large portions of the system in a single day.

Track geometry cars used by the New York City Subway also measure: In the United States, the Federal Railroad Administration (FRA) has a fleet of seven geometry vehicles as part of its Automated Track Inspection Program (ATIP).

ATIP cars conduct operational surveys of the Nation's rail transportation network to determine railroads’ compliance with Federal Track Safety Standards and for trend analysis and technology advancement.

[12] In the United States, railroads are looking into new ways to measure geometry that cause even less interference to train operations.