The car may be king in Fairfax County, but students there soon may not be allowed to learn to drive one during school hours.

School Superintendent Robert R. Spillane wants to stop offering the behind-the-wheel portion of driver education during the school day, and instead require students to take their road training after hours, on Saturdays or in summer.

His proposal, which is on the School Board agenda for discussion tonight and a vote Dec. 3, is expected to face strong opposition from students who would be inconvenienced and from driver education teachers who say safety standards would be lowered.

Spillane said yesterday that his proposal is designed to end the practice of pulling students out of academic classes to take in-car instruction. Classroom driver education would continue during the school day for now, he said.

"The mission of the schools is an academic mission, and we've got to unclutter the curriculum," said Spillane, who previously suggested paying driver education teachers less than academic teachers.

Spillane said students are so eager to obtain their licenses they will take driver training no matter when it is offered. Drivers younger than 18 are required to take 14 hours of in-car instruction and 36 hours of classroom instruction to obtain a license in Virginia.

Fairfax is the only area jurisdiction that pulls students out of academic classes for their road training, and its fee -- $75 -- is the highest in the region. Most local school systems offer the training at no charge. From September 1986 to August of this year, 2,580 Fairfax County public school students took in-car instruction during the school day, 1,695 took it after school and 1,011 took it during the summer.

The District and Arlington, Prince William and Loudoun counties teach the road portion of driver education during school hours, but students are not removed from academic classes. Alexandria and Prince George's, Montgomery and Anne Arundel counties do not offer on-road training when school is in session.

Some Fairfax students are expected to complain about Spillane's proposal because 500 fewer students could take in-car instruction during the school year, and in some cases students would be delayed from taking it until several months after they turned 15 years, eight months, the age of eligibility for a driver's license.

"Being a senior, I don't have much sympathy for those in need of driver education," said Urvi Patel, a student government representative at Lake Braddock Secondary School in Burke. But she said juniors and sophomores who have not taken the class probably will protest because "it would hit them harder."

School officials concede the proposal would make it more difficult for students who work or are involved in extracurricular activities to take in-car instruction, and would force more students to learn how to drive under rush-hour conditions.

More students probably would take on-the-road training from more expensive commercial schools, whose graduates have poorer safety records, they said. And they noted that the proposal would require $99,000 in additional vehicles and salary costs.

Some driving instructors are upset because the proposal would require the county to hire part-time instructors, who they say are not as well-trained. "I'd hate to send these kids out to some hack," said Red Jenkins, a classroom driver education teacher at Woodson High School who formerly taught the on-the-road course. "In English class, if you get an 'F,' you might not lose your life."