Traffic concerns and environmental questions after decades of car manufacturing were debated Wednesday night, as Ryan Cos. hosted the third public meeting about its upcoming development of the former Ford Motor Company site.

Ryan, the Minneapolis-based developer chosen by Ford in June to transform the site into what St. Paul officials hope will be a high-density urban village, said Ford has cleaned the site to meet state standards for residential property and more formal traffic studies will be done soon. Ryan has spent the previous two meetings taking the pulse of the site's neighbors, including gauging neighborhood preferences on features ranging from streetscapes to building and housing styles.

On Wednesday night in the auditorium at Highland Park Middle School, officials asked neighbors to submit questions during the meeting's opening 10 minutes that they addressed during the presentation's final hour.

Many of those questions had to do with traffic, parking and how to get many of the thousands of residents expected to move in over the next 10 years to not bring a car with them. In all, many seemed pleased to get at least some answers.

"I've been really happy with how Ryan has approached this," said Kevin Gallatin, president of the Highland District Council. Still, he said, "density remains a big question."

Ryan has yet to tip its hand as far as how many residents it will try to accommodate in what is expected to be a substantial new neighborhood-within-a-neighborhood. But at its last public meeting in mid-August, officials promised not to build more than 4,000 housing units. And, regarding commercial space, Ryan officials Wednesday said they were aiming to develop at the low end of the range recommended for the site.

While Ryan officials said they will soon release a more complete vision of the site, one of the largest redevelopment opportunities for St. Paul in generations, they shared a handful of their intentions: a promise to plant at least 1,000 trees, set aside more than 50 acres of public access open space and build nothing with 10 stories or more. They said about 20 percent of the units will be affordable housing, interspersed throughout a mix of apartments, condominiums and senior living communities.

Ryan has been praised for welcoming community input. Officials acknowledge that may change for some after Ryan unveils its plan, expected next month.

City officials and many residents are pushing for a 21st-century urban village featuring retail, commercial and residential areas. The city estimates that by 2040, 1,500 people could be working at the site, with 4,320 to 7,200 residents. City officials have said the site has a potential redevelopment value of $1.3 billion and possible new tax revenue of more than $20 million annually.

But others cringed when the City Council last year approved a master plan that offered parks, transit access — and higher density multifamily housing. Opponents to the city zoning plan worry about traffic and parking woes that thousands of new residents could bring to neighboring pockets of quiet streets and stately single-family homes.

Construction at the site could begin as soon as 2020, with many projects completed in the first five years, said Mike Ryan, market leader for Ryan's north region. In all, officials said the site would take about a decade to build out.