Revenue service began today on the first light-rail public transit system in Houston's history, built after a 20-year debate.

Opening ceremonies began on New Year’s Day when a silver train broke through a banner and rode through a cloud of confetti and the cheers of government leaders.

Houston, one of America's most polluted cities, was the last major metropolitan area in the United States without a public transit rail line.

When the first train made its run through the city Thursday, people gathered along the route to wave and take pictures. Service on the train the rest of the day was free.

Traffic was light today, the first day of paid service, and there were a few reports of a stalled train, according to the Houston Chronicle. But by late morning, several lines became very crowded.

The Metropolitan Transit Authority of Harris County spent $324 million in the past three years constructing the 7.5-mile line that is the focal point in a planned 80-mile-long system.

A series of elections, funding questions and political controversies has kept the city without rail and contributed to a smog problem.

More trains are due to begin service later in the month.