The pop-up Porch at 30th Street Station struggles to transition to a grown-up park

In many ways, the history of the Porch at 30th Street Station neatly tracks the rise of the millennial generation in Philadelphia. The DIY public space on Market Street came into existence during the Great Recession, just as millennials were starting careers and moving into their first apartments. Opened in 2011, the Porch prized many of the same qualities they favored: spontaneity over formality, flexibility over permanence, creative whimsy over design with a capital "D."

Now, many millennials are settling down, entering into commitments, acquiring homes, and buying nice furniture. And so is the Porch.

Amtrak just rolled out a preliminary design for a permanent version of the successful pop-up, which it calls Station Square. In place of the Porch's brightly hued picnic tables, goofy swings, and planters made from retrofitted sheep troughs, there are granite pavers and artfully sculpted tree pits. The plan calls for a formal water feature.

It's all very grown up and appropriate. But what happened to the fun?

The design, by two New York firms, !melk and FXFowle, is still in the early stages and likely to undergo revisions, but it highlights the difficulties of translating the free-wheeling sensibility of a pop-up into a plaza meant to be with us for a good half-century. In their attempt to create a respectful gateway to Philadelphia's great art deco train station, the designers have stripped the plaza of the convivial ambiance that made the Porch such a popular space. It's as dull as a hospital entrance.

To understand what makes the Porch special (even at a time when Philadelphia seems saturated with pop-ups), let's go back to those pre-2011 days. What should have been a vibrant transit gateway to West Philadelphia was then nothing more than a traffic island wedged between Market Street and the chaotic inner road ringing the station. Pedestrians trying to reach the entrance risked their lives dodging cars. A huge area between Center City and the university felt like a no-man's land.

The Porch did more than just make it safer for travelers to get to their trains. The brainchild of the University City District, the pop-up was inspired by the pavement-to-parks movement that was then sweeping American cities. New York had just created the first instant park by annexing a stretch of Broadway and setting out lawn chairs. The University City District went a step further. After scattering loose tables and chairs around the traffic island, it brought in food trucks and began scheduling lunchtime concerts, farmers' markets, and other events.

Though the original Porch design (by Ground Reconsidered) was bare bones, the shaded seating and activities transformed the barren traffic island into a welcoming refuge. Overnight, the Porch became a destination for office workers and neighbors, as well as a pleasant spot for travelers to pass the time. Plenty of homeless folks gathered there, too, yet even on a recent Sunday afternoon, they were outnumbered by families. I saw a group of women on the way home from church joyfully pile onto the swings, which were introduced after Groundswell Design refreshed the space in 2015. The whole thing cost less than a million dollars.

Of course, pop-ups were never meant to be permanent, and Amtrak has good reasons for wanting to upgrade the plaza. As part of a larger plan to develop the empty land around the station, the railroad needs to improve the 30th Street's tangled vehicle circulation.

This aspect of the FXFowle/!melk redesign represents a huge advance over what now exists. The ring road and awkward parking zones would be eliminated. The design team has reduced the vehicle drop-off area on the east side of the station to a compact, U-shaped driveway. A second driveway on the north side would provide short-term parking for pick-ups and drop-offs.

The configuration is informed by a new reality: Because increasing numbers of travelers are using ride-hailing services to access the station, Amtrak wants to carve out a dedicated waiting area in the underground space where rental cars are currently stored. A portion of the area would also be dedicated to taxi queuing, which would keep them from clogging the streets around the station. The main weakness with the plan is that there may not be enough short-term parking spaces, but Amtrak says it will modify the plan to add slots on the station's east side.

The beauty of consolidating pick-ups and drop-offs into a more compact zone is that it doubles the size of the pedestrian plaza and extends the apron to the station's front door. If Drexel University's planned Schuylkill Yards "innovation district" takes off, the area around the station will become dense with new offices and apartments, increasing the need for places where people can eat lunch and relax.

The university plans to start work soon on its own park, Drexel Square, across from the station on 30th Street. But it's a relatively small space. Station Square will be twice the size of the Porch, bigger than Dilworth Park. Rina Cutler, Amtrak's director of planning and development, predicts the number of people passing through the park will double to 200,000 a day within the next three years. Later this year, Amtrak plans to advertise for a master developer to oversee its development effort, she said.

That's why it is so important for the landscape architects to infuse some of the Porch's spirit into the plaza.  Though !melk's lead designer, Jerry van Eyck, has worked on several imaginative designs, including the hills on New York's Governors Island, Station Square is disappointingly formulaic.

Too much effort has gone into creating a canopy of trees, which will never get as big as the renderings suggest. Because the plaza is a cap over the Northeast Corridor tracks, the trees need huge planters to thrive. The design scatters enormous petal-shaped tree troughs across the space. The huge planters will merely form a cattle chute, directing travelers to the station doors. Because people don't naturally face one another when they sit on planters, the seating is inherently less sociable than tables and chairs. The planters' size also cuts down on Station Square's flexibility, making it harder to offer programming.

The other strange feature is the array of polka dots embedded in the paving. They're meant to represent the columns supporting the plaza cap, but what passerby would guess that? The design treats the plaza as a piece of patterned fabric, rather than space inhabited by real live human beings.

As the Porch's pop-up transitions into a more mature form, the designers need to figure out how to infuse its playful spirit into its permanent form. That's a challenge, but no one ever said growing up would be easy.