If you think Vancouver is crowded now, just wait.

By 2025, the population of the Lower Mainland will jump by a whopping 574,432 people, according to the Greater Vancouver Regional District's estimates. In other words, we need to make room for an extra city of Vancouver (current population: 545,671).

From a planning perspective, there are two solutions: move these new folk farther out, into bungalows in the distant suburbs, í  la The Brady Bunch; or move them up, into a city in the sky, Jetsons-style.

For the sake of our health, cutting-edge planner Larry Frank hopes we make like the Jetsons, minus the flying bubble car and the skyway commute.

In his research, Frank, currently the UBC chair of sustainable urban transportation systems, found a direct link between health and urban sprawl. People who live in densely populated walkable neighbourhoods, such as Vancouver's West End, are up to 35 percent less likely to be obese than their sprawling suburban neighbours and contribute far less to air pollution because they do not drive cars as much. His latest book, Urban Sprawl and Public Health: Designing, Planning, and Building for Healthy Communities (Island Press, 2004), authored with Howard Frumkin and Richard Jackson, helped spotlight his research in publications from the Globe and Mail to the Vancouver Sun.

His diagnosis for Vancouver? It's very healthy but at risk.

"In Vancouver, civic leaders had the foresight and vision to create what is very likely the best example in North America where enough new growth has been focused in the downtown and designed in a way that the resulting urban environment is extremely inviting and livable, to the extent that condos often sell before buildings have even broken ground," Frank told the Straight in a phone interview. His previous academic home, Atlanta, Georgia, is extremely sprawling and has a much less vibrant downtown. The investment in highways there, he said, has fuelled sprawl and siphoned vitality from the downtown.

"To the contrary, Vancouver did lots of things right, historically, including the set-aside of public open space in the downtown area- including Stanley Park and the waterfront-and shied away from building freeways. To me, we should be doing everything we can to support what is already happening on the ground. We have the best model in North America for creating a walkable downtown in this era of the car, and it's only getting better."

Frank is confused as to why, then, the provincial government is planning to expand the Lower Mainland's network of highways to facil?itate sprawl and allow more cars into the city each day. He sees the provincial government's Gateway program as a threat to the quality of life in this region. Based on past research, he notes that it will facilitate air pollution, energy consumption, obesity, and sedentary lifestyles. There's a need for more capacity for freight movement and to address congestion problems on the Port Mann bridge, but he believes that there are other solutions.

Pointing to what he calls a mounting set of evidence, Frank said: "Building these highways in the absence of strict growth controls will only result in more congestion and auto dependency. At a minimum, provincial proponents of the Gateway program should consider other options before diving into a highway-only solution. Why not learn from the mistakes of others? It's a lot cheaper."

By 2009, the B.C. government plans to widen the Sea to Sky highway; build a new bridge between Maple Ridge and Pitt Meadows; build a perimeter road along the south bank of the Fraser River; expand the North Fraser perimeter road; twin the Port Mann Bridge; and widen 33 kilometres of the Trans-Canada Highway between Vancouver and Langley, all with the aim of reducing congestion. Frank's research indicates that within 10 years car traffic will just increase and the congestion will be as bad as, if not worse than, it is now.

"You cannot build your way out of congestion," he emphasized.

It's not just Langley mini-mansions versus Vancouver condos, though. Vancouver itself needs to move in new directions to cope with its problems.

In the dusty, former flea-market parking lot at King Edward and Kingsway, a 391-suite residential spaceship from planet Yaletown is landing in the spring of 2007. Surrounded as it is by green, tree-lined streets and 1950s-era stucco houses with plush lawns, some planners consider the new glass-and-cement King Edward Village a healthier community vision than imitating the sprawling, relatively affordable lots of southeast Vancouver. The project's catch phrase is "Where Vancouver is moving to".

That sums things up. Vancouver is-surprise, surprise-moving to a model that values small condos, vertical communities, and a Chunky-soup mix of retail, office, and residential over the postwar picket-fence dream. It's called intensification, and it includes basement suites, infill housing, and condos, condos, condos. Most often, it's presented in terms of affordability, an increasing population, and smaller, modern families.

"Instead of building on new green space, to accelerate growth use existing urban areas such as parking lots," Cheeying Ho, the executive director of Smart Growth B.C., told the Straight. "When there's increased density, there's less need to drive."

Think of King Edward Village, The Carlings and Arbutus Walk (the two projects total 754 units in Kitsilano), Salsbury Heights (16 units in Grandview-Woodlands), and Koo's Corner (six units in Strathcona) as giant vitamins for the city, then. The dense mix of residences, retail, businesses, and green space is designed to get people walking and biking-Vancouverites' two favourite activities for keeping in shape, according to a Sport B.C. study.

You can't buy a suite in one of the above developments, though, for much under $250,000. With the ever-escalating price of housing downtown, Frank worries that Vancouver may become a New World Paris. The nightmare would be a wealthy swank neighbourhood downtown, and workers forced to live at the end of a long highway commute.

Once again, the solution to this public-health issue is urban planning. Frank prescribes an aggressive, affordable housing strategy for the city, to allow people of all income levels to enjoy a clean, walkable, fit lifestyle.