Obama Foundation considers closing roads in Jackson Park

When Olmsted and Vaux designed parks, the idea was for visitors to engage in pleasure driving, whether by horse and carriage or by automobile, said Charles Birnbaum, president and chief executive of the Cultural Landscape Foundation, an educational and research organization.

"Slower-speed travel is what should happen," he said, whether by walkers, runners or bicyclists. On an interim basis, Chicago could experiment with closing the roads on weekends, he said, as New York's Central Park has done.