New Orleans Public Service Incorporated was the operator of transit services from September 22, 1922 to July 1, 1983. It took over New Orleans Railway & Light Co. and all "paper" companies whose streetcar lines NORy&L operated. NOPSI sold its transit interests to the Regional Transit Authority.

Under NOPSI ownership the last new streetcars (800-972 and 1000-1019) were purchased. All streetcar lines except St. Charles were discontinued between 1925 and 1964. Motor buses began operation in 1924; their service area was greatly expanded to include most of the urbanized portion of Orleans Parish by the end of NOPSI's ownership. Trackless trolleys were used from 1929 to 1967 on eight routes.