The protests of Adelphi residents may block -- or at least delay -- the move of an engineering school from Montgomery County to a proposed new $5.5 million campus in Prince George's County.

The Capitol Institute of Technology is seeking a special exception from county zoning laws to allow construction of a three-building, 900-student campus on 20 acres zoned for residential development.

Neighbors of the property, in Adelphi along Powder Mill Road, complain that the institute would exacerbate traffic problems.

The residents have promised to show up in force at pending public hearings, and say they would rather see as many as 32 houses built on the site, between Cherry Hill Road and Glenmore Drive.

"They're trying to butcher land that was set aside for single-family homes," said George Miller, cochairman of the Hillandale Gardens Citizen Council. "I don't like the idea of taking an area zoned for 32 homes and bringing in 900 to 1,800 students. People can't get out of their driveways now and all I hear is more and more plans for more and more traffic."

Anticipating a public outcry, the county zoning and hearing examiner scheduled two hearings on the subject -- Jan. 28 and Feb. 4 -- instead of the one public hearing usually set for zoning applications.

After the hearings, the examiner will make a recommendation to the Prince George's County Council, which has final say on zoning matters.

If public opinion continues, it is unlikely that the council would approve the school's construction plans, said Del. Timothy F. Maloney (D-Prince George's).

Maloney praised the institute as an example of the kind of clean, quality industry he would like to see in Prince George's but, he said, "the concerns of the neighbors have to be recognized."

A meeting last month, called by the institute to explain its plans, drew nearly 200 area residents, Maloney said. Angry members of the crowd shouted their opposition to the school. At one point, an attempt to restore order elicited a chorus of boos, according to Maloney and others who attended.

William Troxler, president of the Capital Institute of Technology said in an interview recently that the resident's fears are groundless.

Similar concerns were voiced by Kenington residents when the institute moved to that Montgomery County neighborhood 10 years ago, Troxler said, "and their concerns haven't proved out. We've been a quiet, unobtrusive neighbor."

Troxler said the institute spent two years searching for a place to move from its cramped quarters in Montgomery County.

Adelphi residents claim the college would quickly grow into an 1,800-student facility with dormitories and a high radio antenna. Plans for such a larger campus were drawn up at the request of state and county planners who wanted to study the theoretical impact of the largest school that could be built on the site, Troxler said.

"We have no intention of building a campus of that size," Troxler said. He said he expects to move into the new campus in 1982 with 700 students. Enrollment would not exceed 900, he said.

Troxler, who said he is hopeful the county will approve the campus plan, pointed out that it was approved by the Maryland-National Capital Park and Planning Commission.

The State Highway Administration reported that with 1,800 students the school would not have an adverse impact on traffic, as long as extra lanes are built for cars turning into the school parking lot.

The institute's present campus is on a two-lane neighborhood road in Kensington, Troxler said.

"We do not create traffic problems here. It is inconceivable to me that, by moving to a state highway, with a 40-mile-per-hour speed limit, the same institution would suddenly create a problem," he said.

Also called Rte. 212, Powder Mill Road meanders from Rte. 1 in Beltsville through residential Adelphi neighborhoods to heavily traveled Riggs Road and New Hampshire Avenue.

"It is a major artery carrying traffic toward Washington," Troxler said. "The traffic is there, irrespective of whether we move there."

Troxler said he would like neighborhood residents to call for road improvements instead of opposing the construction of the college campus.

A 1973 proposal to widen the road drew fire from area residents who "were adamant that they wanted Powder Mill to remain the narrow, windy country lane that it is," Maloney said.

With three buildings, landscaped grounds and parking lots covering four acres, 15 or 16 acres around the campus would be left untouched as wooded land, Troxler said.

The nonprofit institute will have spent more than a year and $500,000 on various studies and plans to find out whether it can build on the parcel of Adelphi land, Troxler said.

"It's going to hurt us a lot if it (the zoning exception) doesn't go through," he said. "It will delay us at least two years."

Both hearings on the issue are slated for 7 p.m. at the High Point High School auditorium in Adelphi.