Two plazas, with different views

A well-designed public plaza is an invitation to socialize, a civic nexus where people come together to relax, enjoy the city, and feel pride of ownership in their neighborhood.

Right now it's possible to judge how well such public spaces work -- or might work -- thanks to the opening of a new plaza in Cambridge and the display of designs for another on view at the Boston Center for the Arts.

The new Shapiro Family Plaza , which runs along the Massachusetts Avenue side of the Porter Square Shopping Center , fails on all counts. Its blaring black-and-white striped motif is more than uninviting; it's repellent. Folks looking for a place to sit for a spell on a nice day will likely flee into Dunkin' Donuts rather than linger on the plaza.

Porter Square bustles, and its people need a place to come to rest. The city of Cambridge has been working to streamline traffic and make the area more hospitable. The square is -- minimally -- easier to navigate on foot than it used to be.

Earlier this month, the city unveiled the plaza, designed by artist Toshihiro Katayama with help from landscape designer Cynthia Smith .

Katayama, who was a professor at Harvard University for decades and was the director of its Carpenter Center for Visual Arts, has plenty of experience with large-scale public design, especially in Japan. He has a taste for bold geometries; MBTA riders will know the star mural he designed for the State Street station. The stainless steel ``T" outside the Alewife station is also his handiwork.

Porter Square is a visual and aural cacophony in need of quiet space. The heavy traffic, the competing styles of architecture and art -- from Victorian brownstones to the banal shopping plaza to the modernist T station (and Susumu Shingu's airy kinetic sculpture) -- called for a serene axis around which all the activity might spin. Instead, Katayama has extended a pattern that spans all the nearby streets. He's built a giant, forbidding crosswalk.

As in a crosswalk, you won't want to stop. Jagged granite boulders crop up gloomily (don't try to sit on one; you might hurt yourself). Katayama added the boulders as a nod to New England's landscape. The same goes for two stone walls, which have little regional authenticity because, probably for practical reasons, they're not dry stone walls.

The walls and the boulders are jarringly naturalistic set against the pavement's Modernist geometry. Black-and-white steel banners that match the pavers rise from the ground; what's merely aggressive underfoot turns downright confrontational when it asserts itself into the visitor s' space.

Perhaps it was a mistake for Cambridge to designate the plaza as a public art project rather than a landscape design project. Either way, it went through a process that included vetting and approval by neighbors and a jury. What were they thinking? High -- not to mention lousy -- concept has trumped comfort.

The Boston Center for the Arts must walk that line between art-friendly and pedestrian-friendly design for its proposed new plaza. The design competition is near its end: jurors have chosen five plans out of 66 submitted. All are on view in the Cyclorama through Sunday. On Saturday, anyone interested can attend a community review to discuss the designs. The winner will be announced in September. (In the interests of full disclosure, for a few months in 1988I worked for a nonprofit that BCA President Libbie Shufro ran.)

The BCA project is larger and more ambitious than the Porter Square fiasco. This plaza encompasses the entire block from Berkeley Street to Clarendon Street. The aim is to make the block into a unified campus, easily navigable, in a way that integrates the historic architecture of the neighborhood and introduces the arts center's programs to the public.

My favorite is Daniel Cho's plan, a place for the community to gather. He proposes that the large area of the plaza in front of the BCA be both park and performance space: a sunken, inviting area with a reflecting pool can be covered over with a deck to create a stage. Add to that a jazz cafe and balcony off of Hamersley's and -- at least in the warmer months -- the joint is jumping.

Two designs -- one by Aaron Dorf , Kirsten Hively , Rebecca Hutchinson and Adam Modesitt from the Harvard Graduate School of Design; one by Stephen Stimson Associates, Landscape Architects, Inc. -- suggest large-scale video projection on the plaza of whatever's going on inside the BCA. Outdoor video is unquestionably the wave of the future, as arts organizations strive to make their walls metaphorically transparent.

In both cases, the ideas are too big and not thought through. Do we really want to turn Tremont Street into a drive-in, with video projected on the facade of the BCA, as the Harvard group proposes? The steel mesh projection pavilion Stimson has thought up makes more sense. Ultimately, though, art exhibitions and theatrical productions rarely make good video; it would add up to white noise on the plaza.

The simplicity of the other two proposals would pull the sprawling plaza together. Eric R. Hoffman and Tony A. Patterson of patterhn integrate the plaza with a wood floor that would be easy on the legs and help you find your way. Rachel Broek proposes a transparent canopy. Like patterhn's idea, it would unify the architecturally diverse elements of the block, but I'm guessing it would be a hassle to maintain, given the local pigeon population.

Any one of them beats turning the BCA Plaza into an oversize crosswalk.