Subway and bus fares will rise again in March. The only questions are by how much and for which riders.

When the Metropolitan Transportation Authority’s board members meet this week, they are expected to discuss proposals for a 4 percent increase in fares and tolls across the system’s trains, buses, tunnels and bridges. The fares are scheduled to rise every two years as part of the authority’s long-term revenue plans, but details of the upcoming increase are still being worked out. Riders will have a chance to weigh in at public hearings next month.

One proposal would raise the base fare for subways and buses by 25 cents to $2.75, while increasing the bonus on pay-per-ride MetroCards to 11 percent from 5 percent. A second proposal would keep the base fare at $2.50, but reduce the current pay-per-ride bonus.

Under both plans, weekly and monthly MetroCards would cost more, according to Mitchell H. Pally, a longtime board member who confirmed the details of the proposals, which the authority has not released publicly yet. Weekly passes would go up by $1 to $31, and a monthly pass would increase by $4.50 to $116.50, Mr. Pally said. There would be a similar 4 percent increase in fares and tolls for rail lines and tunnels and bridges.