It also recommends ditching the design's most scorned element: the stainless-steel lookout towers. WRT's plan would use the savings for other design improvements.
The coalition commissioned the report last month after learning that construction on the long-delayed $54 million project would begin in the summer.
Center City residents have demanded changes in the design since at least 2001, but made no headway with city engineers during the Street administration. Their hope is that Nutter and his cabinet will take a fresh look at the bridge, which is an important neighborhood link and a dramatic gateway to Center City from I-76.
"We had a good meeting last Monday with city engineers, but we know this is going to take support from elected officials," said James C. Campbell, a professional planner who is coordinating the coalition's opposition to the current design.
An administration official said Nutter was willing to consider changes, but first wanted a briefing on the WRT report. After receiving such a briefing Friday, City Council President Anna Verna, whose district includes the bridge, agreed to support the redesign, a spokesman said.
Coalition members acknowledge there isn't much time to implement WRT's recommendations, which are mostly modest refinements. No cost estimates were included with the report.
Engineers closed the span to heavy trucks last year after chunks of concrete began sloughing off and dropping into the Schuylkill. The upper portions of the structure date to the 1920s and were constructed on the foundation of an 1876 drawbridge. Yet despite the steel patches and broken concrete, the bridge's stylishly turned metal railings and sculpted overlooks give the crossing a warm, welcoming character.
Though the coalition no longer holds out much hope that the new bridge will be as architecturally rich, the group wants to ensure that the surface feels like a continuation of a city street rather than an interstate overpass, Campbell said.
According to the WRT report, the best way to soften that highway character would be to widen the sidewalks, upgrade the decorative railings and lights, and add amenities like crosswalks and bus stops.
Because the width of the bridge deck is fixed, WRT suggests that city engineers eliminate the dedicated turning lanes on the west end, which speed access to I-76.
Saving that space would give designers room to widen the sidewalks on the new bridge. Since there will be two traffic lanes in each direction, WRT contends that dedicated turning lanes aren't essential, especially given the relatively low volume of traffic. The main concern comes from the University of Pennsylvania, which wants to be sure ambulances do not get stuck behind turning cars.
In addition to widening the sidewalks, WRT advised the city to move the streetlights and crash barriers. The current design places those fixtures along the edge of the bridge. WRT's planners would shift them inward, between bike and car lanes.
The move would create a generous buffer zone between walkers and drivers. Bicyclists would also feel safer.
Shifting the federally mandated crash barriers also would open up new design opportunities for the bridge's architect, H2L2. The firm would be free to create a more decorative railing along the edge of the bridge, and add planters and pedestrian-scale streetlamps, replacing highway-style "cobra-head" streetlights.
The WRT report enumerates a long list of small design revisions to slow traffic and improve safety.
Some are common sense. For instance, while city engineers call for a bike ramp connecting the bridge to Schuylkill Banks park, they make no provision for bicyclists to cross the bridge and switch direction. WRT calls for a crosswalk at the ramp.
The city's bridge design, by Gannett Fleming Inc., also eliminates a bus stop across from SEPTA's University City regional rail station. WRT wants the city to restore the stop and include medians where departing bus passengers can stand before crossing to the station.
"Good grief, how can we have a regional rail station that goes to the airport and not provide a bus stop?" Campbell asked. "We need a 21st-century bridge, with connections to recreation and transportation, not an SUV bridge."
The Schuylkill, which is about the same width as the Seine in Paris, was once spanned by pedestrian-scale, architecturally distinctive crossings. But as the old masonry bridges at Spring Garden, Chestnut and Walnut Streets came up for repair, they were replaced with standard girder-bridges that resemble highway overpasses, down to their industrial green undercarriages.
Contact architecture critic Inga Saffron at 215-854-2213 or firstname.lastname@example.org.
Read a draft of the plan for the South Street Bridge at http://go.philly.com/bridgedesign