Mr. Hugh Creegan:

We can go to any year but generally we go about 15 or 20 years after opening. If there are only two people on a corridor, a taxi is needed for them. If there are 10,000 people, it is a DART or metro. In between those two, a bus route will serve between 2,000 and 3,000 passengers per direction in an hour. With a figure above that, one goes to light rail. That will take 7,000 passengers an hour. After that, one moves to metro or heavy rail.