The proposed Falls Church school budget for 1983-84, which calls for an increase of $234,000--or 4.5 percent--over this year, will be given its first public hearing Tuesday at 7:45 p.m., in the school board offices in Daniel Elementary School.

The budget proposed by Superintendent Warren Pace would save $20,000 by eliminating behind-the-wheel driver's education training for 70 to 75 students but would continue in-class drivers' education, said Douglas Scott, executive assistant to the superintendent.

Students interested in continuing the behind-the-wheel training would have to pay for it and take the training outside regular school hours. The cost would be between $75 and $125 and the instruction would be provided by private firms.

Fairfax County school officials are taking a similar tack this year, with their proposed school budget calling for students to pay a $60 fee for driver training classes.

In his budget message, Falls Church's Pace proposed that the school system also delay roof repairs as well as buying a school bus and new textbooks.

According to Scott, Pace's "austere" budget also calls for "a low" 3 percent pay raise for the 78 teachers, whose salaries constitute more than half of the school budget.

While school enrollment is again expected to drop from about 1,025 students this year to about 1,000 next year--there were 1,060 last year--Pace said the change is too small to warrant layoffs. Leesburg to Consider Pipestem Lot Curbs -

The Leesburg Town Council tonight will consider regulations to restrict development of pipestem lots, which are accessible only from a lane or driveway and have no frontage on town streets.

The town is proposing that no more than three houses be permitted to use such private driveways and that they be no longer than 250 feet. No town regulations now govern such developments.

About eight pipestem lots have been developed recently in two town subdivisions, town manager John Niccolls said.

The proposed amendments, first considered last month, are an attempt to balance what town officials have called an efficient way of developing some difficult properties with concerns that they both increase density and are difficult for police and fire trucks to reach.