City transportation officials want to make changes to 21 of Oahu’s 100 city bus routes this summer, giving riders until May to have a say in the final plan.

The move to save on operating expenses and avoid raising fares comes as bus ridership is on the rise, increasing 2 percent in March from the same month last year, and as gas prices in Hawaii — the highest in the nation — continue to set rec­ords.

Some changes proposed to take effect in June and August will decrease the frequency of service, while most will move routes to different streets or end them in different locations, but only a couple of routes will be eliminated.

"It doesn’t deprive anyone of service," Director of Transportation Services Wayne Yoshi­oka said. "We won’t screw people from getting to work or wherever they’re going."

If city officials have made a misjudgment, missed something, miscalculated or were unaware of something, they want to hear from the public, Yoshi­oka said.

"This is not a done deal," said Yoshi­oka. "We will change if necessary, even after we roll the service out."

A revised plan is expected in early May after public input is considered.

At one of the 14 public meetings being held on the proposed changes, a woman in Nana­kuli said that if her bus doesn’t come at 4:30 a.m., she’ll be late for work, said Yoshi­oka. "We’ll look closely at the schedule."

By modifying service, the city hopes to save between $6 million and $7 million as a hedge against numerous hefty operating costs, including diesel fuel — expected to increase by $3 million next year — and labor, Yoshi­oka said.

"We are desperately trying not to raise bus fares," he said. "We’ll see what we can do to squeeze every last bit in moderating expenses."

Twenty-one bus routes will be altered or eliminated, affecting many of the 235,000 riders on average catching TheBus daily.

Yoshioka said only two routes are being eliminated.

Route 231 in Hawaii Kai, slated for elimination in June, is a circulator between Koko Marina and Hahaione Valley.

The other route being eliminated is Route B, which originates in Kalihi and goes into Waikiki. But a similar route (Route 2) will compensate with an increase in service. The new Route 2 will run from the Kalihi Transfer Center, through downtown, McCully and Waikiki, and will add Kapa­hulu Avenue to Kapiolani Community College but will no longer travel on Kalakaua Avenue past the zoo and aquarium.

Yoshioka acknowledges increasing ridership is a dilemma the city faces.

Ridership is particularly high along the Wai­anae Coast, and the city might re-evaluate changes in frequency of buses.

"We’re hoping by shifting around buses, we can accommodate this demand," he said. "Where buses are running partially full, we can transfer to an area where they’re overflowing."

Anita Diaz, who lives in Makaha and works in downtown Hono­lulu, says she depends on TheBus exclusively for transportation.

One proposed change includes reduced service on Route C (Ala Moana Center to Makaha), scheduled to run every half-hour, to once every hour on weekends.

"If you miss the last bus leaving Ala Moana at 8:30 p.m. and need to go to Makaha, you are out of luck," she said. "I missed the last Ala Moana C and had to take the 40 to Makaha Valley Road. At 2 a.m., after waiting for two hours for a 40 to the beach, I gave up and just walked the one mile home."

One controversial change — cutting Kahala and Kapa­hulu from Route 14 — might be a mistake, Yoshi­oka acknowledged.

"After hearing from people, that’s one of those we don’t think we got quite right," he said. "We’re missing something in here."

He said they will rework Route 14 and might alter other routes. Despite very low patronage, "we heard that those few people who do use it are really dependent upon it," he said.

The city also won’t touch some low-patronage areas such as along ridgelines because they provide what is considered "lifeline service": if cut, residents would have no service.

Routes that currently circle the island will be sacrificed for improved service to Wahiawa.

Routes 55 and 52 will be delinked so the 52 will travel only between the Wahiawa Transit Center and Ala Moana Center, whereas the 55 will travel between Ala Moana Center, Kane­ohe and Wahiawa, and turn back around to Ala Moana Center.

Oahu Transit Services, which operates TheBus, will not lay off any of its 900 or so bus drivers, but will reduce numbers through attrition.

Each year, OTS hires 90 to 100 bus operators, but won’t be hiring as many in the future, Yoshi­oka said.