The Capital Area Transit System plans to lease 10 additional buses for at least the next six months to supplement its fleet, which has been plagued by maintenance issues.

The CATS Board of Commissioners agreed Tuesday to spend no more than $4,400 per bus as CATS negotiates a contract for the next several months. CATS CEO Bob Mirabito said the agency wants to lease 10 refurbished Gillig buses, 1999 models, until they can invest in a permanent fix for the fleet.

The total cost of leasing the buses for six months would be $314,000, which includes the cost of leasing them as well as delivery fees. Depending on how long it takes to chart a long-term path for the buses, the vehicles might be leased for up to 18 months.

“As we all know and we’ve said for months, our fleet leaves a little bit to be desired,” Mirabito said. He said the refurbished buses should be able to perform at the necessary level despite their age, though he cautioned that refurbished buses have shorter life spans if the board would choose to purchase one in the future.

Now that the board has approved the measure, Mirabito said, CATS will send a mechanic to inspect the buses. If they have no problems, CATS will enter an agreement to lease them.

It would take around four weeks for the new buses to arrive and have the necessary equipment installed before they start running.

The board also approved a measure to spend more than $340,000 to buy six replacement vans for CATS on Demand.

Maintenance issues with CATS’ aging fleet have long impeded the agency’s ability to deliver more reliable on-time service.

There are 86 buses in total, but 28 are past their useful life and prone to breakdowns. Another 27 of the buses, purchased in 2005 from a now-defunct company, have a litany of maintenance problems.

Last quarter, CATS averaged 4.5 bus breakdowns per day — an improvement over the previous quarter when it was almost seven breakdowns a day.

Earlier this month, service problems reached a critical mass when CATS had to take more than 20 buses and three vans off the street in one day.

“That’s way above normal,” Mirabito said in an interview earlier this month. “I think it was a combination of normal break downs plus not necessarily having our parts come in on a timely fashion.”

Four routes were affected, and eight trips were canceled that particular morning because CATS had fewer working buses than needed to run at full service levels.

People waiting for those buses on the affected routes would not have had a bus come at the scheduled time, but another bus would have come between 15 minutes and an hour later, Mirabito said.

By the next day and a half the agency was running at regular service levels, he said.

Five new buses that had previously been ordered are expected to arrive at the end of this month or the beginning of June. Four other new buses are scheduled to arrive in 2016.

New buses cost about $400,000 each and take more than a year to arrive.