Prince William and Loudoun counties are at the center of Northern Virginia’s future job and population growth and a controversial parkway connecting the two is imperative to the region’s future, state Secretary of Transportation Sean T. Connaughton said Tuesday in a rare meeting in front of Prince William supervisors.

Connaughton, a Prince William resident who was elected twice to the county’s at-large seat, addressed some of his former colleagues and a packed board room primarily gathered to hear about the proposed the Bi-County Parkway.

Residents across the county fear that the 10-mile parkway from I-66 in Prince William to Route 50 in Loudoun would affect their property and way of life, as well as the county’s protected Rural Crescent and historic Civil War ground near the Manassas National Battlefield Park.

Connaughton outlined $1 billion in projects that are already funded for Prince William – including on I-95 and I-66. He then outlined his and the state’s reasons for the north-south parkway, and attempted to address supervisors’ and residents’ concerns.

The Virginia Department of Transportation projects enormous growth in the Prince William-Loudoun corridor by 2040, he told the board. “How are we going to move these people back and forth?” he asked. Job growth is evolving, he said, and future residents will want jobs where they live, not on long commutes on crowded corridors.

He sought to address several widespread concerns. One is that Route 234 will be widened and truck traffic from I-95 would increasingly use the route to reach Dulles airport. VDOT officials have, in the past, pointed to increased cargo traffic as a selling point for the road and the entire north-south corridor. But Connaughton told board members that the route won’t be used by many trucks.

“We have no intention to widen [Route] 234,” Connaughton said. He also said that the thousands of residents who live along and near Route 234 – and fear living along a new “Outer Beltway” – will not experience huge truck traffic volumes.

Air freight going to the airport is “very low volume, but very high value,” Connaughton said.

The sometimes feisty crowd didn’t seem to believe much of the presentation and numbers that showed the benefits of the parkway. When Connaughton said that traffic on I-66 would drop when the parkway is built, the crowd laughed. Many believe that the parkway would be used by many drivers to connect to I-66.

Connaughton said to assembled reporters after his presentation that transportation projects engender controversy.

“Transportation projects by their very nature are big, ugly and messy,” he told reporters. “When they’re operating, folks say … ‘Why didn’t you do this sooner?’”

The tensest exchange occurred between Supervisor Peter K. Candland (R-Gainesville) and Connaughton. Candland said that Connaughton’s effort to downplay cargo traffic when VDOT presentations had emphasized it in the past was disingenuous. “This is the frustration people have,” Candland said.

He also sought to get an answer about whether the state would build the parkway before Route 234 is shut down through the park and a bypass built around the Civil War ground. That scenario is preferred by Prince William officials and the National Park Service, which controls the park.

Connaughton said he would work with Candland and the county to address concerns. “That’s a little frustrating because I didn’t hear an answer to the question,” Candland said. It’s unclear whether the county could keep Route 234 open, used by thousands per day, if the state and federal government wanted it shut down.

Connaughton told reporters that he has never appeared before a local body before. But he said he’s never been asked. “This is my ‘hood,” Connaughton said, as to why he appeared. “I personally believe this is imperative for Prince William County.”

Did he change any minds by coming? “No, not at all,” he said.

A number of elected officials, residents and advocacy groups attended the meeting. State Del. Robert G. Marshall(R), who represents the area, said he remains convinced the project would benefit developers, not commuters. “The private money tail is wagging the public road construction dog,” Marshall said.

Connaughton sought to emphasize that he and VDOT are simply looking to get a broad legal agreement, called a “Section 106” agreement, signed off on. The estimated $440 million project has not been funded, he said.

“We’re just trying to get the paperwork done … and the federal approval so we can make a decision about whether to build the parkway,” he said.