A new era for the Innsbrook corporate center could begin officially this week, pending approval from Henrico County’s Board of Supervisors.

The board will hear a request Dec. 11 by Highwoods Properties to redevelop a 39.46-acre section of the 630-acre corporate center as an urban mixed-use tract, allowing for as much as 2.3 million square feet of commercial and residential development – including 1,230 residential units. The Planning Commission recommended the plan for approval at its Nov. 8 meeting.

Supervisors rezoned most of the site – 36 acres – to the then-new urban mixed use classification as part of a larger case in 2005 that sought to breathe new life into the Far West End community by allowing a variety of uses in close proximity to each other, similar to the communities of West Broad Village and Rocketts Landing. Highwoods’ current proposal would establish conditions on the entire 39.46-acre site, which is located generally between Cox Road, Sadler Road and Nuckols Road.

During a work session last month, the board heard its first formal presentation about the proposal for the project.

Planning Director Joe Emerson told supervisors that his staff generally supports the plan but objects to a proposed Highwoods proffer that would require the county to pay for right-of-way acquisition and permits related to road improvements for the project. (Highwoods must construct an additional eastbound lane on Nuckols Road between Sadler and Cox roads and an additional westbound lane on Nuckols from Lake Brook Drive to the I-295 northbound ramp as part of the project.)

“We don’t feel we should be obligated to absorb the cost of those items,” Emerson said.

Some neighbors of the site have expressed concerns about traffic, which already is snarled along Nuckols Road during morning and evening commutes, and the proposed height of some buildings, the tallest of which would be 250 feet, or about 16 stories.

But Emerson said that Highwoods’ proposal – which would limit buildings within 150 feet of existing residential development to 45 feet in height and those between 150 feet and 300 feet of such development to 80 feet in height – was consistent with recommendations of his department’s 2010 Innsbrook Area Study. That study set guidelines for a variety of future urban mixed use projects in the community, in order to establish consistency in building heights, landscaping, streetscaping, parking, signage and a variety of other features.

Still, “there is no doubt that you’re going to be able to see the tall buildings,” Emerson said.

Board Chairman Dick Glover (Brookland District) and Supervisor Pat O’Bannon (Tuckahoe District) both expressed some concerns about a proposed one-lane roundabout that would be constructed at the intersection of Sadler Road and Sadler Place, about 600 feet south of Nuckols Road.

“Drivers around here, I don’t think they’re used to this, and it bothers me a lot. . . that this is more an impediment,” O’Bannon said.

But Deputy County Manager Tim Foster told the board that the roundabout – which might cost about $200,000 and could be the first public roundabout built in the county – would be safer than a traffic signal, which would cost between $150,000 and $250,000. Traffic at the intersection wouldn’t yet warrant a signal, and locating an additional signal so close to Nuckols Road could create traffic flow challenges, he said – whereas a roundabout would be more effective in keeping vehicles moving.

Foster noted that roundabouts are different from traffic circles; the latter typically are larger, involve more lanes and more merging traffic and may present more opportunities for confusion or traffic accidents.

Roundabouts, he said, are smaller, typically involve just one lane of traffic and are used in less-congested areas to keep traffic flowing better than it would otherwise. On the rare occasions when accidents do occur at roundabouts, they’re usually less severe because vehicles are traveling at a lower rate of speed than they would be otherwise, he said.

Glover conceded that he would support the plan if it were deemed the safest option.

Some residents have expressed concerns that construction of the roundabout would eliminate direct access from Sadler Road to Nuckols Road, but Emerson said that wasn’t entirely accurate. The new roundabout would shift Sadler south into its old roadbed but still theoretically provide drivers the chance to connect to Nuckols without stopping.

Responding to residents’ concerns that more development would worsen traffic, Emerson agreed that the initial impact could boost traffic numbers. But he said that the ultimate outcome of urban mixed use development often is a reduction in traffic, because some residents also work and/or shop within the same community.

“The UMU district is intended to provide flexibility not otherwise available in the zoning ordinance to achieve a unique destination, conveying a “sense of place,” and providing a desirable destination to live, work, and recreate,” planners wrote in a report about the proposal.

Emerson told the board that as the project takes shape and residents move in, some benefits would become noticeable.

“You’ll have people coming and going over the whole day – not just at two peak times,” he said.