A light bar snap bracket assembly includes an elongated rail member, multiple light modules, multiple snap brackets, and multiple locking devices. The light modules are disposed within the rail member channel in a line of light modules extending longitudinally from a first light module disposed at the first end of the rail member to a last light module disposed at the second end of the rail member, the line of light modules defining pairs of adjacent light modules. One of the snap brackets is disposed intermediate each light module in each pair of light modules, one of the snap brackets is disposed intermediate the first light module and the first end of the rail member, and one of the snap brackets is disposed intermediate the last light module and the second end of the rail member. Arm segments of each snap bracket extend longitudinally over tabs extending from the light module sides, of the adjacent light module half portion, with the tabs being received within the notches of the arm segments. Catches on the snap brackets engage shoulders of the rail member whereby the snap brackets lock the light modules to the rail member. Biasing segments of the locking device urge the snap bracket resilient members radially outward, locking the snap bracket catches in engagement with the rail shoulder.