Residents in one of the nation’s first planned communities — designed as a place where people could live, work and play — are at odds over new development some fear could result in more growth than the town can support and ruin its character.

The arrival of Metro’s Silver Line nearly four years ago spurred a frenzy of development not seen in decades. High rises. Town­houses. Retail and office space. And with the second phase of the rail line expected to open in 2020, the construction boom is likely to intensify.

Those who moved to Reston say they were attracted by founder Robert E. Simon Jr.’s vision of a diverse, all-inclusive community. Some of those residents say the recent rapid development is taking away from the community’s suburban feel. Others say the new projects are a fulfillment of Simon’s vision of a true planned community where residents can find everything they need — work, schools, shopping and recreation — all within easy reach of their homes.

Now, as the Fairfax County Board of Supervisors prepares to approve zoning amendments to push those plans forward, some residents are calling for a reset. Build less, they say, or in the case of at least one planned road — don’t build at all.

“People who moved here bought the zoning, and now they are trying to change that,” said Tammi Petrine, a longtime Reston resident who serves as co-chair of Reston 20/20 and one of the leaders of the Coalition for a Planned Reston, a group that has mobilized to fight the changes.

“We are a suburb, and we want to stay a suburb,” Petrine said.

The vision for a new Reston is the product of nearly 200 public meetings. The result, two blueprints approved in 2014 and 2015, lays out how it will grow over the next two decades. The plans concentrate development near three Silver Line rail stations and around “village centers,” mixed-use areas already home to shops and, in some cases, apartment buildings.

Near the Metro stations, the plans could add more than 38,000 residences, a network of parks, a performing arts center, schools and other amenities over the next several decades.

The changes are dramatic. In one instance, four high-rise buildings will replace the one- and two-story medical buildings, 30 office condos and a bank that previously occupied the 8.4-acre parcel just north of the Wiehle-Reston East Metro station. The new development will include a 14-story office tower, a 23-story hotel and two residential buildings with 540 units, 16.5 percent of which will be set aside as affordable housing.

Fairfax Supervisor Catherine M. Hudgins (D-Hunter Mill), who represents Reston, said she understands this is a big change from the low-rise office complexes scattered throughout the community, but she said the plan is a “continuation of its founder’s original vision.

“Reston has always had a higher density” than other communities, Hudgins said. “But at the beginning it was not developed to those levels.”

Petrine emphasized in an email that she and others in her group “are not selfish NIMBYs. Rather we are energized to fight for preservation of our planned sustainable, human-scale community where neighbors interact for the common good.” (NIMBY stands for “not in my back yard.”)

But the reality is that staying suburban is no longer an option for many communities. With the Metropolitan Washington Council of Governments projecting that the Washington region will add more than 1 million people over the next 30 years, local governments have spent years trying to figure out where to put them.

At the heart of the debate is how to manage population and job growth in a region where skyrocketing real estate prices have put homeownership out of reach for many and where traffic congestion worsens each year.

The answer is the kind of focused development happening in Reston — homes and jobs near transit, mixed-use developments in areas where parking lots and single-story shopping centers once dominated.

Paul DesJardin, director of community and planning services for COG, said it makes good fiscal sense to concentrate development in areas where there is easy access to transportation. It’s also the best use of the limited funding available to build and maintain new infrastructure, he added.

Canaan Merchant, who has written about Reston’s development for the online site Greater Greater Washington, said he was attracted to the area in part because there were enough transportation options that his family didn’t need to have a second car. He likes the idea of a more walkable Reston, but he doesn’t want to see it overrun with high-rises.

“I’m not totally ‘Rah-rah! Let’s pave everything over,’ ” he said. “I’d prefer we do it in a way that keeps people as close to jobs and transportation.”

Petrine said she has a different view.

“If you really think you want to be in a really dense, urbanized community, please move there,” she said. “We are not that. If you enjoy that, we don’t think you’re bad, but we don’t think you understand what Reston is about.”

The Coalition for a Planned Reston and the Reston Association, a group that represents residents living in the planned community developed by Simon, outlined their concerns in separate letters to Hudgins. Their requests — peppered with such phrases as planned residential communities, planned residential mixed-use communities, ADUs and FDUs — can be hard to translate into plain English. But they boil down to asking the county to limit development around existing village centers, rethink their calculation for the number of people allowed per acre, scrap plans for a new road and set an overall maximum for Reston’s population at 120,000. Under the approved plan, Reston’s population of 61,000 could more than double to just over 140,000, county officials say.

David Bobzien, president of the Reston Association, which has also expressed concerns about the community’s future, said this is not about stopping development but about putting more controls in place to ensure that the community’s roads, schools and recreational centers are not overwhelmed. He said the issue is particularly sensitive for residents around village centers, where most of the homes are single-family residences. Planners say adding a mix of housing in those areas will make them more vibrant, but Bobzien said residents are concerned that too much development will alter the character of their neighborhoods.

And then there’s the effect on traffic. Already, he said, rush hour in Reston spans two to three hours.

“We have not kept up with the infrastructure, not kept up with roadway improvements,” he said. “It really is the traffic that is the biggest concern.”

Last month, planning officials responded to the groups’ concerns, saying that while they were willing to clarify language, any significant changes to planned densities were unlikely. Given the resources invested in creating the 2014 and 2015 plans, officials said their general policy is not to consider changes for at least five years from when the plans were approved, wrote Fred Selden, Fairfax’s director of planning and zoning.

Officials said they did not agree with the groups’ request to abandon plans for a road that would connect American Dream Way and Isaac Newton Square.

“Staff believes the proposed future roadway is important to provide needed connectivity for planned redevelopment of the Isaac Newton Square area and will provide congestion relief by serving as an alternative route to Sunset Hills Road,” Selden wrote.

But as for the 120,000 population cap, Selden said staff members would consider including a “future population estimate or target for future growth.”

He closed by saying that while officials are open to more discussions, county officials are not in favor of the changes sought by the groups.

“In summary, staff is open to clarifying several areas in the Reston Master Plan as noted in our response and continuing the work with the Reston community to address their concerns about the future,” Selden wrote. “However, staff does not support the proposed change to the Reston Master Plan that would affect land use, density of intensity recommendations.”

The Fairfax County Board of Supervisors is expected to take up the zoning amendments this spring or early summer. The amendments are needed to bring the zoning ordinances in line with plans approved in 2014 and 2015. The board will hold public hearings before taking a final vote.

Meanwhile, Petrine and Bobzien said their respective groups are still formulating their responses to the county’s letter.

“We hope that we can continue to work with the county to make some changes,” Bobzien said.

But Hudgins said she remains convinced that the blueprints for Reston’s future are the best path forward.

“I don’t think it will overwhelm us or make us less of a community. I think it will make us better,” she said.