No, the runaway trash truck didn't have anything to do with it. Plans had been afoot to give Logan Circle (and the Benjamin Franklin Parkway) a face-lift long before a wayward sanitation vehicle plowed into the Swann Fountain this winter. On the docket was a new 16th Street entrance, new trees and two major museums. "There is lots of positive energy focused on the Parkway," says Mark Focht, executive director of Fairmount Park, which owns Logan Circle — the epicenter of the coming grand revival.

Marking the beginning of a wide-ranging project, the Pennsylvania Horticultural Society (PHS), the Fairmount Park Commission and the Philadelphia Art Commission will begin digging up the famous park today. All the hedges, flowers and benches will be pulled up while a tree surgeon will remove 12 paulownia "empress" trees that currently circle the fountain. (A fast-growing, short-lived species, these 70-year-old paulownias are on their last roots.) They will be replaced by 12 new paulownias that are currently growing at the Longwood Gardens. The PHS wants the new trees to be the same size and shape.

Paulownia is prized wood, particularly in Japan, where ornaments made from it can reap a pretty yen. The park has made a deal with the tree surgeon, who will keep the wood as payment for his services. Also, a few small pieces will be given to a Moore College of Art sculpture professor for his wood-carving students.

Once called "Northwest Square," Logan Circle was a site of public executions and burial plots until the early 19th century, when it was renamed after Irish-born Philadelphia statesman James Logan. The park's present circular form was constructed in the 1930s. The new park will retain its Depression-era design. The only visible change will be the new ornamental flower beds, inclined for passing commuters' viewing pleasure. Bankrolling the reconstruction are the Pew Charitable Trusts and the City of Philadelphia, which have given the project grants of $750,000 and $400,000, respectively.

What's next for the Parkway? While plans to open a museum to house a collection of Calder works were scrapped this week, the multimillion-dollar Barnes collection of post-Impressionist art will be leaving its Merion gallery for a spot near the Rodin Museum.

When it was first conceived a century ago, planners dreamed the Parkway would become a central artery, flowing with the lifeblood of a great American metropolis: institutes of knowledge, vast residences, vibrant businesses and throngs of pedestrians. The age of the automobile ran over that idea for generations, but the Parkway may finally be zooming toward its long-delayed renaissance.