Columbia subject headings:
Local transit--Research--United States.
Local transit--Technological innovations--United States.
Transportation--Research--United States.
Transportation--Technological innovations--United States.
Harvard subject headings:
Local transit--Research--United States.
Local transit--Technological innovations--United States.
Transportation--Research--United States
Transportation--Technological innovations--United States.
Princeton subject headings:
Local transit--Research--United States.
Local transit--Technological innovations--United States.
Transportation--Research--United States.
Transportation--Technological innovations--United States.