Gabriel Sanchez says there was no good public transportation in Mayaguez, Puerto Rico, where he grew up. “I just learned to walk fast,” he says, adding that he has long had a dream to create mobility for others.

Now, Sanchez plans to help cities around the world redesign their transportation systems — improving entire systems for buses and trains — whether it’s changing the routes, changing the fares, or making the schedules more reliable.

The 24-year-old graduate student, who is in the transit research group at MIT, studies civil and environmental engineering. “It’s a dynamic field,” says Sanchez, who plans to earn a master’s and Ph.D., and who came to MIT last fall after working in San Juan for a year helping to improve that city’s bus system.

Sanchez, who speaks English, Spanish, and a bit of Italian, first came to MIT at age 16 to participate in MIT’s Minority Introduction to Engineering and Science (MITES), a six-week summer program for high school juniors interested in careers in science, engineering, and entrepreneurship.

“I absolutely loved it. It was a life-changing experience. I tested my limits of learning and of what I could do. It just opened up my world to new opportunities,” says Sanchez, adding that one big lesson was “that I actually could get into MIT!”

He applied to the Institute as a freshman and was accepted. “But I was not able to attend because the financial offer was not enough for me and my family,” he says. “I decided to make the best of it.”

Determined to keep a good attitude, instead he enrolled at the University of Puerto Rico, where he held a 4.0 average and excelled in his activities. For two summers during college, he did return to the Institute to serve as a teaching assistant in the MITES program.

Last year, Sanchez reapplied to MIT as a graduate student. Funding now has made it possible for him to study at the Institute. Currently a recipient of an MIT Presidential Fellowship, he says: “The fellowship has given me so much freedom, including the freedom to define my research without restriction. I am very grateful.

“Donors help to connect talented students and talented faculty to do great research that potentially results in improvements, whether it’s in the area of artificial intelligence, developing medical devices, or even working on cures for cancer,” he says.

“A donor might think that they’re just supporting me, but really, when people take a bus or train five, or 10, or 20 years from now, maybe the system will work better for thousands of people, just because of them.

“I think about that a lot.”