TDI

TDI or Trailer Density Index is a statistical measurement describing the ratio of Prefabricated housing to Stick-built dwellings within a one square mile area. A TDI of 1 indicates there is an equal number prefab and stick-built structures within the square mile of interest.

Sunnyvale Trailer Park's TDI was estimated at 54 after the tornado struck resulting in $1.1 million dollars of improvements.