Gov. Arnold Schwarzenegger vetoed a bill Wednesday that would have given more students access to career-and technical-education programs, calling the proposed changes piecemeal and suggesting a more-comprehensive overhaul of career education in California.

The bill, sponsored by state Sen. Michael Machado, D-Linden, and approved by the Legislature, would have allowed 15-year-olds to enroll in Regional Occupational Programs and Centers, which help prepare students for careers in a variety of hands-on fields.

Under current law, a student must be at least 16 or have a special waiver to enroll in such a program.

Machado said Thursday that the bill aimed "to simplify the process."

"Not everybody's going to go to college," Machado said. "Young people come out from these programs and are readily employable."

Doug Martin, who oversees vocational-education programs for the San Joaquin County Office of Education, said forcing students to wait to sign up could put them at risk of dropping out of school before enrolling in a career-focused program.

The county office served almost 3,000 students in these programs last school year, Martin said. Many other school districts in the county also operate career and technical programs.

In a statement, Schwarzenegger said the state needs to make better use of the hundreds of millions of dollars allocated for career and technical education, and he suggested the state develop "a comprehensive plan ... instead of enacting piecemeal changes, as this bill suggests."