Port Authority of Allegheny County buses will make more trips each day under a plan to boost the efficiency of the county's public transit system, potentially easing crowded lines.

But other lines will be consolidated or cut altogether, potentially causing headaches for some riders who must walk farther to bus stops or find alternate methods of getting to work, stores and family members.

While the proposal might make the authority more efficient, it might make the city as a whole more wasteful, said Carrick resident Janet Asbury, who does not own a car and takes the 51C and 54C to reach her job in Oakland.

"Pittsburgh is trying to be a green city," said Ms. Asbury, one of about 100 people who testified at an all-day public hearing held at the Marriott City Center on the authority's proposal to change and eliminate some routes, and to raise fares. "We need to encourage people not to drive their cars."

The Port Authority's plan will cut under-used and inefficient routes to streamline the system while increasing fares to raise $4 million needed for next year's operating budget. The plan would merge or relocate 69 bus routes and eliminate some of the authority's 16,000 stops; consolidate routes that buses take through Downtown to simplify service; and create transit centers for transfers.

The fare for a one-zone bus trip would remain $2, while the fare for a two-zone bus trip would increase from $2.60 to $3. The authority wants to eliminate the three-zone category, rearranging the system into just two zones.

The T system surcharge would increase from $2.50 to $3 for a one-zone trip and from $3.10 to $3.50 for a two-zone trip.

Bus service is being eliminated entirely for only a small minority of riders, according to the plan. Jim Ritchie, authority spokesman, said about 400 riders, or less than one-half of one percent of daily passengers, will lose their bus routes and have no public transit alternatives.

In addition to testimony at yesterday's hearing, the authority has received about 50 letters and 500 e-mail messages commenting on the proposed changes.

In addition, said Mr. Ritchie, the authority has already addressed some groups directly about the changes and in many cases worked out solutions over the past two years. The public has until Sept. 30 to make comments, which can be submitted on its Web site, tdp.portauthority.org, in writing, or by calling 412-566-5437 or the TTY line at 412-231-7007 from 9 a.m. to 3:30 p.m. on weekdays.

After Sept. 30, the authority will examine the suggestions prior to its Oct. 23 meeting.

"We have to read through them all," said Mr. Ritchie. "We're looking for things we might have missed."

Many people who testified yesterday were worried that their bus route will be cut under a transit plan set to go into place next year.

"The demand for the bus is significant," said Melanie Steven-Cosnek about the 13G route in Ross, which is among those that could be eliminated.

She said that bus is usually full and that people in the North Hills who rely on it would have difficulty finding alternatives.

"Please keep the 13G," she said.

Others worried about the effects of eliminating or consolidating routes on elderly, the disabled and low-income parents with young children, who use the bus to reach everything from grocery stores and doctors' offices to jobs and family gatherings and will have to walk farther to their stops.

Instead of making it more difficult for riders, the authority should make the system more accessible and offer incentives -- a discount for people using park and ride facilities, for instance -- to draw new riders, said Christina Schreckengost of Carrick.

"I understand you're a business, but the business is revolving around people," she said.