GROTON — With plans to dignify the town center with pairs of stone markers at key entranceways, members of the Main Street Committee (MSC) seemed to be of two minds in welcoming visitors. One offers them a friendly greeting and the other warns that local traffic laws will be strictly enforced.

It was that contrast in language that drew some concern from the Historic District Commission (HDC) Tuesday when committee member Jane Bouvier answered questions about the project.

First proposed to the Board of Selectmen (BOS) almost a year ago, the proposal to place the stone markers downtown is part of an effort to spruce up Main Street while imparting an important message to visitors.

In addition to Bouvier, members of the MSC include police Chief Robert Mulhern, Highway Surveyor Thomas Delaney and assessor Edward Kopec.

Plans call for the markers to be placed at two places along Main Street, Bouvier said. One would be located across the road from the new Groton Exchange filling station, and the other adjacent to the entrance of Powderhouse Road leading onto the property of Lawrence Academy (LA).

However, because the location on Powderhouse Road falls within the downtown historic district, the committee was required to present its plans to the HDC for approval.

The markers will rest on concrete plinths and come to about 5 by 8 feet in size. Material for the stones will be donated by the Croteau family’s Colonial Stoneyard that will incise the facing with a legend suggested by Bouvier reading, “Welcome to Groton Center; please drive safely; traffic laws strictly enforced.”

“Materially, it’s appropriate,” said commission Chairman Daniel Barton.

While they feel the proposal was not a bad idea, some members of the HDC felt the phrase, “Traffic laws strictly enforced,” sounded too harsh. They asked if another phrase making the same suggestion in a friendlier way could be used. Commission members also wondered if the order of the three parts of the message could be rearranged.

The language used on the stone was negotiable, said Bouvier.

Other concerns raised by the commission included landscaping surrounding the stone, the texture of the stone, the size of the stone and its location, and the typeface to be used for the lettering.

A question was raised by Chairman Daniel Barton as to whether the dimensions of the stones could be changed from something low and wide, which made the markers look too much like tombstones, to a more vertical design.

With no decision reached on the issue, the hearing was continued until Jan. 17.

Also Tuesday, the commission continued a public hearing on plans by LA to build an addition to the 3- year-old Ferguson Building, which houses a library, auditorium and mezzanine/office area.

According to Daniel Quaile of Mt. Vernon Group Architects, designers for the project, renovation plans call for pushing back the stage and expanding seating capacity in the basement level of the auditorium. Space in the library would also be increased. To the rear of the building, a completely new structure will be added for use as classrooms for drama students and an entrance lobby.

At a hearing in July, Quaile assured the commission that the existing library building would alter little regarding the view from the quad or Powderhouse Road. Instead, the major change will occur in the rear of the building facing the parking lot where the addition will be constructed on the same level as the basement auditorium.

Tuesday, Quaile brought samples of the kind of materials to be used in constructing the new addition including bricks, molding, framing and an outdoor lamp that is to be mounted on posts around the property.

Showing the samples to commissioners, Quaile said that artificial material will be substituted for building materials such as wood and stone because of their durability and ease of maintenance. The new materials, painted and fashioned to match existing architecture, will be designed to preserve the integrity of the original building.

“I think that product is perfectly appropriate,” said Barton. “The overall plan is well conceived.”

But the commission did have other concerns about the project that focused on lighting, especially in the parking lot facing the new addition. Members feared that lights there would create too much glare amid a viewscape including the Gibbet Hill area.

With lots of new material to study, the commission continued the meeting Jan. 17.

Finally, Tuesday, the commission voted to approve new signage for Sims Cleaners and Tailors, 127 Main St., and for the Boutwell Elementary School located on Hollis Street.