"If we have a 10 a.m. class, the most logical time to have two shuttles would be at 9:50, not 10, when class is already starting, and I know for certain that there has only been one shuttle at 10," Del Canto wrote.

Justin S. Wohler '02, also a Pforzheimer resident, said he anticipates severe crowding problems as the weather turns cold and wet.

"There should not be a last-minute change to the schedule when Harvard realizes that many students are forced to walk to class in the rain and snow," Wohler said. "The schedule should take this into account now."

Wohler criticized "gaps in the service," adding that few shuttles take students from the Quad to the Stadium and athletic facilities.

Shuttle Service officials said the schedule is an annual work in progress. Carl A. Tempesta, operations manager for transportation services, said he is open to hearing the concerns of students.

"We intend to get involved in the House committees again to get feedback from the student body and to see what we can do to help," he said.

Many undergraduates in the Quad and in Dunster and Mather Houses rely on the shuttles, which also provide transportation for faculty, administrators and graduate students.