Odebrecht USA says it complies with the U.S. embargo on Cuba and “is remote and distant from and has no contact with,” COI Overseas Ltd., the firm involved in the Port of Mariel project for the Brazil-based parent company Odebrecht S.A.

The ceremony began after 10 a.m., and passengers started boarding the first train around noon. Some riders were upset that transit officials did not provide specific information about when the service would begin. Transit officials told reporters that service to the public would begin sometime after the ceremony.

“Apparently after weeks of notifying riders of Metrorail that the Orange Line would start on July 28th, someone forgot to inform the riders that it would NOT be running in the morning,” wrote Sid Kaskey of South Miami in an angry e-mail message to The Miami Herald.

While the trains leaving the MIA station seemed to be operating smoothly, the ride from Dadeland South to MIA had a few false starts.

Originally scheduled to depart at 12:15 p.m., the northbound Orange Line train didn’t leave the station until 12:45 p.m.

But for those who waited, the ride was ultimately as smooth as the new rails to MIA.

Still, a few passengers were confused by the new service. One woman who was looking for the Tri Rail train dashed out at Earlington Heights, the wrong station for the Tri-Rail transfer.

But for the most part, conductors gave clear instructions on transfers. On-board attendants helped guide passengers at stations. And platform-side attendants helped lost travelers with further instructions.

At the new MIA station, at least two dozen attendants were on call helping to answer questions. And clear electronic message boards showed train schedules.

Most information seemed to be in English, though. Bilingual attendants and station managers helped non-English speaking passengers. Announcements at the MIA station were in English and Spanish, but they were sometimes hard to hear.

For all its benefits, the new service provides a small reprieve for Nilsa Rosado. For 10 years, the 44-year-old Transportation Security Administration agent has traveled a convoluted route from her home in Homestead to her job at MIA. A series of transfers from bus to train made her daytime commute almost three hours long. Service delays made her night time commute even longer.

Now, Rosado said, she will save anywhere from 20 to 30 minutes on her trip home.

“It’s definitely going to be a big change,” Rosado said. “I’ll get home earlier and finally get some sleep.”