The 31.5-mile weekday-only service now runs from Orlando north to DeBary. Plans call for an extension to DeLand and south through Kissimmee to the Poinciana area.
It's the first new first new commuter rail system to open in the United States in three years, according to Reuters.
In its first day of service, trains were full and an hour behind schedule. "It's just astounding," SunRail spokesman Steve Olson told the Sentinel about the number of people riding the trains.
SunRail is offering free rides through May 16. The $2 base one-way fares kick in May 19, according to the Sentinel.
Follow Road Warrior on Twitter at