COLUMBIA — Superintendent Mick Zais is again requesting $34 million for new school buses and asking lawmakers to close a teacher bonus program to new entries.

Zais told a House budget-writing panel Wednesday that more than 60 percent of South Carolina’s state-owned buses are more than 15 years old. He says it would take $34 million to comply with a 15-year replacement cycle legislators passed in 2007, the same year a Post and Courier investigation found that the Palmetto State’s buses were the oldest, most polluting and least safe buses in the nation.

His agency’s last major purchase of 342 buses was in December 2012. Zais asked for $34 million last year. Legislators approved $23.5 million, which could buy 280 buses. The agency hasn’t yet received all of that.

Zais also repeated his recommendation to close an incentive program for teachers who earn a national certification, which provides an annual bonus of either $5,000 or $7,500 for 10 years.