Like Brigadoon, a fleeting vision of the Spring Garden Street Greenway will appear along one block of Spring Garden for one day only. And while the pop-up greenway will last for only one September Saturday, organizers hope the memory will linger on and stoke public support to really build the greenway.

On September 20, community volunteers are building a temporary version of the Spring Garden Street Greenway to showcase the possibilities. The westbound lanes on the 900 block of Spring Garden Street, where the Reading Viaduct passes overhead, will be filled with a block party – with food, drinks, and music – as well as a design demonstration for the future greenway.

The Spring Garden Street Greenway would transform the 2.2 miles of Spring Garden Street, river-to-river, with a protected landscaped bikeway in center of the street’s wide median and add pedestrian amenities like curb bumpouts and improved lighting. The greenway would provide a continuous trail connection between the Schuylkill River Trail and Delaware River Trail segments being built. The project would make Spring Garden Street into Philly’s most complete street – our truest balance between cars, transit, bikes, and pedestrians – and promises to make the streetscape look a whole lot more inviting.

The greenway concept has been floated for more than five years, gaining recent steam through robust public input sessions, conceptual designs by Interface Studios, and a final report [pdf] completed last year by the Pennsylvania Environmental Council.

Construction costs for the Spring Garden Street Greenway were estimated in last year’s report at $20.3 million, and the project is expected to stimulate about $40 million in economic activity related to its construction. Add to that the longer-term benefits to health, mobility, safety, recreation, connectivity, property values, and quality of life and building the greenway starts to look even more enticing. But until that funding is identified, it’s time to cultivate broader public support and build political momentum.

To help people experience the greenway volunteers have blended ideas from Better Block Project complete street demonstrations and borrowed a few pages from Park(ing) Day (September 19, this year), to create a pop-up street intervention.

“We want people to get out there and feel what the greenway might be like and also what a great corridor and a great block might feel like,” explained Tony Spagnoli, program manager at Pennsylvania Environmental Council (PEC), which is helping advance the greenway plan and support volunteers.