Montgomery County Executive Charles W. Gilchrist proposed a $1.24 billion, six-year building program yesterday that would shift resources to road and school construction to cope with record development in the Washington area's second-fastest growing county.

The capital improvements budget for fiscal years 1987-92, which would boost spending by $200 million over last year's recommendation, is expected to be approved, if not increased, by the County Council in an attempt to counter school crowding and traffic congestion.

The program would be financed in part by $542 million from the sale of general obligation bonds, $18 million from "impact fees" imposed on developers to pay for roads and $148 million in "pay as you go" cash.

"We understand the problems of congestion and the need for expansion, particularly in the upper part of the county, and this budget is responsive to that," Gilchrist said. "It is an expanding budget to meet exanding needs."

County Council member David L. Scull said he foresaw no immediate problems with the spending plan.

"I think it is pretty close to what we voted last year," he said.

Gilchrist earmarked a record $259.5 million to build two new high schools and 10 new elementary schools and fund 65 projects renovating or building additions to existing schools.

An additional $257.1 million was targeted for road improvements, including the construction of car pool lanes for Rte. 29, a highway that runs north to Howard County and is one of the county's most congested.

The proposed appropriations for roads and schools, 42 percent of the total budget, represent significant increases over previous budgets. However, in the case of school construction, the executive's recommendation fell $64 million short of the $323 million requested by the Board of Education.

The executive cut most of the money from the board's school building modernization program. He also postponed construction of a $13 million vocational education high school, which Gilchrist said was not needed to meet demands for new classroom space.

"The [school board's proposal], while it may represent an ideal approach to modernization, places a very heavy burden on the county at a time when we must fund a very large construction program to provide essential new capacity," he said.

In a prepared statement, School Superintendent Wilmer S. Cody said he was pleased with the executive's effort to provide "sorely needed" classroom space but said he disagreed with the proposed cuts.

The recommended budget, the last of Gilchrist's eight-year administration, reflects sweeping changes in both the county's growth rate and the number of children enrolling in county schools over the past five years.

Since 1979 more than 40,000 homes have been built in the county. The population has jumped from 579,000 to 610,000, proportionally the highest increase in the region after Fairfax County, according to census figures. Most of the growth has occurred in the northern I-270 corridor between Gaithersburg and Germantown.

By 1990, the population is expected to grow by more than 40,000, and development plans call for the construction of up to 55,000 homes, according to planning forecasts.

County planners already see a "baby boomlet" of young children entering public schools, which has boosted elementary grade enrollments.

The new road projects proposed by Gilchrist included the widening of roads in Silver Spring and Germantown and the construction of a connector between Md. Rte. 124 and Shady Grove Road. Also, $30 million was earmarked for the addition of new lanes on Rte. 29 to be designated for car pool use. Five other road projects have been accelerated, Gilchrist said.

In all, 38 of the 66 road projects are needed to meet the requirements of the county's Adequate Public Facilities Ordinance, which says that new development cannot occur until public services exist to serve it.

Total funding for transportation, which also includes mass transit, bridges, sidewalks, parking facilities and other improvements, will top $396 million during the next six years.

Gilchrist also recommended spending $2.2 million for day care programs in county schools because of a growing number of single-parent families (11.5 percent of the county's 207,000 households) and two-income families (63 percent of all households).

With adjustments for inflation, the proposed capital budget is actually $400 million less than the six-year capital budget in 1981, said William H. Treworgy, chief of the county's budget division.

The percentage of the budget funded by general obligation bonds has increased substantially, a reflection, Treworgy said, of the decline in funds from state and federal government.