Boston officials have answered the pleas of a group of Emerson College students who had lobbied the city to extend the time allowed for pedestrians to cross at Boylston and Tremont streets, citing the dangerousness of the busy intersection.

Gina N. Fiandaca, commissioner of the Boston Transportation Department, said in a recent letter to assistant professor Catherine D’Ignazio and her students that crews retimed the traffic signals to increase the walk cycles by a total of four seconds.

The department already had been reviewing the feasibility of extending the walk cycle as they updated traffic signal timing plans in that area. But officials said they appreciated the students’ request, which capped months of extensive research conducted for a class project.

“Receiving input from your students when we were reviewing the Tremont Street corridor was very helpful to us and we appreciate the Emerson community’s insight in this important project,’’ Fiandaca wrote. “I am also pleased that the outcome proved to be a positive and valuable lesson in the benefits of civic engagement for the students involved.’’

In December, students Kate Bartel, Kelsey Aijala, and Tori Knoerzer put together a proposal for D’Ignazio’s civic art and design studio class calling for a longer crossing period at the intersection so people would no longer need to scramble to safety before cars began to whiz by.

To promote their idea, the students circulated a petition online and promoted the message on social media. They also gained support from the school’s president, Lee Pelton. They then sent their findings to the city.

Before the recent changes, three of the four crosswalk signals at the intersection had 24-second cycles. For seven seconds, they displayed the “WALK’’ symbol. Then, for 13 seconds, they flashed the “DON’T WALK’’ sign. During the last phase, the signals showed a solid “DON’T WALK’’ message.

Now, the “WALK’’ phase will be 11 seconds long, said Fiandaca. (The fourth signal at the intersection allowed for a longer crossing period and wasn’t changed.)

Although the students had asked for a slightly longer “WALK’’ phase — 12 seconds — D’Ignazio said she was satisfied that her class had played a role in bringing the need for change to the city’s attention.

“Real change is hard and these students accomplished it!’’ she said.

Steve Annear can be reached at steve.annear@globe.com. Follow him on Twitter @steveannear.