PHOENIX — Thousands of people packed into train cars Saturday as this car-crazy city launched its new light-rail system amid criticism that ridership would be limited by urban sprawl and the area's grueling summer heat.

Despite lingering questions over whether the system would be of much use, several riders waiting at a busy station applauded the new trains as convenient, good for the environment and economical.

"I am an environmentalist," said Dean Pedrotti, a hazardous materials inspector for the fire department who rides his bike to work at least once a week. "I have a solar system on my house and generate 90 percent of my electricity. So, to me, this is the right way to go."

The $1.4 billion startup line, which took nearly four years to build, runs from north-central Phoenix through downtown and then east through suburban Tempe and Mesa. More than 30 miles are planned to open in Phoenix, Tempe, Mesa and Glendale by 2025.

Light-rail officials were expecting at least 26,000 riders on average during weekdays. A one-way ticket costs $1.25, but officials are offering free rides through Wednesday.

Abraham Koory, an employee of a printing company in Tempe who already takes the bus to work, plans to use the light-rail system every day to get to his job.

"I think it will be faster than the bus," said Koory, who would have to take a bus to his train stop.

Gloria Celentano, a state employee waiting to take the train Saturday, said she would like to use the light rail system regularly but that taking it would require driving several miles out of her way to a train stop.

"I might as well drive to work," she said.

Still, Celentano said she believed the system would be successful. "I know people at work who are really awaiting its start, because of the commute. It cuts down on everything," she said.

At a ribbon-cutting ceremony, Phoenix Mayor Phil Gordon scoffed at critics who said the system was a waste of money. "Today, you don't hear or see very many of those individuals," he said.

Christopher Robinson, who plans to use the trains because he doesn't own a car, said the trains were appealing because fares would be cheaper than buying gas. But he also thought people would be drawn to it for cultural cachet.

"I think that people in Arizona want to know what it really feels like to be a New Yorker," Robinson said. "This is their little taste."