Capital Area Transit Authority leaders on Wednesday discussed plans to replace their aging fleet in the coming years and entertained the possibility of, in a few years, switching to electric buses.

Standard industry practice is to retire a city bus after 12 years, said CATS CEO Bob Mirabito. The 66 CATS buses average 11.9 years old, he said.

Previous leadership bought new vehicles fitfully, purchasing 28 vehicles in 2005, then going six years before ordering another, Mirabito told the CATS board.

“You don’t want to repeat that mistake,” he later said in an interview.

He and CFO Conner Burns laid out a plan wherein the board can purchase a dozen new vehicles every year through 2020 to replace older units. The board, minus absent members Coletta Barrett and Ken Perret, unanimously approved the ordering of 12 Gillig buses this year. However, due to production and delivery constraints, the buses will not arrive until 2017.

“Unfortunately, it’s not like going down to the car lot, picking one out and driving it off the same day,” Mirabito said.

Over the next five years, each bus is estimated to cost about $400,000 to $450,000 dollars. Federal grants will cover about 85 percent of the cost. Burns told the board CATS has the funding to cover the rest of the expense.

The U.S. Environmental Protection Agency also is offering money in the short-term to help agencies replace older diesel buses with newer models that produce less pollution, Mirabito said.

For at least the next few years, though, all the new buses will run on diesel. CATS Chairman Jim Brandt did note that bus manufacturer Proterra will be offering a demonstration of its electric model at 2 p.m. March 31 in Town Square.

Mirabito expressed interest in going electric, though there are drawbacks. Each bus can cost up to $800,000, substantially more than a diesel unit. Because the electric buses are generally taller, CATS would also have to raise clearances for areas like maintenance bays.

Mirabito said CATS may be able to begin ordering electric buses about 2019 or 2020, about the same time the transit system completes its current fleet replacement.

During the public comment phase of Tuesday’s meeting, one person asked if the new buses will be handicap-accessible. Mirabito explained that some of the older Gillig models in service don’t “kneel” for disabled passengers, but the new units will be compliant with the Americans with Disabilities Act. The old models will be phased out, though he didn’t give a timeline.

Board member Donna Collins-Lewis, who also serves on the East Baton Rouge Parish Metro Council, asked about financing. Burns said CATS can buy nine of the new buses right now. CATS is working with the local congressional delegation to reallocate some earmarked money for vehicle purchases, but the system can finance the rest of the new vehicles as a last resort if necessary.

Follow Steve Hardy on Twitter, @SteveRHardy.