Tree-lined streets. Office buildings and apartments up to 10 stories high. A pedestrian-friendly hub with a historic yet urban feel.

That long-term vision is what Manassas leaders and planners say they want to bring to the small city.

For years, the Manassas gateway along Route 28 and Mathis Avenue has been a hodgepodge of car dealers, gas stations and fast-food restaurants. The gateway, which provides visitors and commuters with their first image of the city, needs updating, city leaders say.

"Route 28 is a missed opportunity," said Deana Rhodeside, whose Alexandria-based architectural and planning firm, Rhodeside & Harwell, was hired by the city to draw up the plans. "Right now, it's a way to get to and from where it is you're going, instead of a place to come to or stop in. We want this to be a place where people can say, 'Gee, now I know I'm in the city of Manassas and this is a nice place to be.'"

This two-mile gateway was developed largely in the 1950s and '60s without an overall long-range plan, Manassas City Manager Lawrence D. Hughes said.

Back then, "most of Prince William County was delighted with any development that happened," he said. "They were just emerging from rural status. The dominant philosophy was that landowners should be allowed to build what they wanted."

Now, looking to boost the city's economy and appearance and give it more of an identity, a group of citizens and officials says it's time for a makeover.

The key to expanding the city and its core is adding density, Hughes said.

"We can't spread out -- we've got to spread up," he said. "There's an axiom that says: . . . When cities stop growing, they die."

Plans call for sidewalks linking shops and restaurants, similar to Arlington County's Clarendon and Ballston neighborhoods and the area near the King Street Metro in Alexandria.

Parking lots would be hidden behind buildings. Small businesses would be combined with large, mixed-use buildings. A fifth, turn lane would be added along Route 28 to ease congestion. Utility lines would be buried.

Officials cautioned that the plans could take years to carry out, depending on market conditions. Yet they say interest is strong. People call daily with interest in putting up residential and commercial buildings, said former mayor John Weber, who is president of Weber & Associates Realty.

"I think there's a lot of interest in that corridor," he said. "But it's not to the degree that's shown in this plan. I don't know that they're at the point yet of . . . putting up high-rises, but everybody is getting calls. . . . It's going to take some time."

Manassas residents, many of whom are not aware of the plan's details, will be asked for their reaction in the next few months. Liz Via, the city's community development director, said planners will alter their sketches as the public weighs in. The Manassas City Council will consider the plan early next year.

Meantime, some question how such small, one-story businesses as Tom's Diner, a popular restaurant along Route 28, will fit into this new Manassas.

The diner clashes with the look officials are seeking. Surrounded by concrete, the restaurant sits in the center of a lot, with cars parked in front. Pushing parking to the back would hurt business, said Elayan Elayan, a co-owner. "We're really short on parking anyway," he said.

In the spring elections, mayoral candidates were split over the plans.

Charles E. "Charlie" Sturms (D) said that at a minimum, construction could disrupt businesses such as the diner. "Nobody has actually satisfied my curiosity as far as how they're going to treat those businesses along there," he said. "There's a lot of successful businesses along there, and they're going to be displaced."

Mayor Douglas S. Waldron (R) supported redeveloping the corridor, saying he hoped it would become the city's "new downtown."

"At the same time," he said, "we're going to continue to concentrate on Old Town, preserving its character."

Other city officials emphasized that Manassas does not want to lose such businesses as Tom's Diner.

"We want to encourage [businesses] to keep their identity," said Lorene Payne, the city's zoning administrator. "We're not trying to make everybody look the same. . . . It's a misunderstanding if anyone feels we're trying to push out the small guy."

Others wonder how redevelopment could affect the city's historic landmarks and districts, including merchants and businesses in Old Town.

Melinda Herzog, director of the city's historic resources and Manassas Museum director, and other preservationists are working with the city to integrate design and transitions between development and such landmarks as Liberia House, the only major structure in Manassas to survive the Civil War. Herzog said that when visitors step onto the property's 18 acres, ideally they would get a feel for life in 1861. "You don't want to see a 12-story skyscraper" on the horizon, she said.

Either way, the redevelopment probably would bring more people to Manassas, which would only help Old Town businesses, said Steve Nelson, a business leader and owner of Old Town's Junction Travel agency.

The changes would not come easily, Herzog said, especially for longtime residents who came to Manassas to get away from urbanization. But if growth is inevitable, she said, it's better to plan for it.

"Good planning can make you feel like you're not in an urban area but still give you that sense of a rural community," she said. "You can have the best of both worlds."

Manassas was sparsely populated in the mid-1950s when development of the city's gateway was underway. A hodgepodge of car dealers, gas stations and fast-food restaurants dominates the corridor along Route 28.Manassas City Manager Lawrence D. Hughes.