I worry about the idea of putting a parking garage below Main Street Gardens for two reasons. The first is the concern referenced a week or so ago about overall quantity of supply, when there is so much parking, that makes driving a breeze, which makes pedestrian life miserable, which in turn chokes a city. With that said, if it is replacing surface lots (which certainly doesn't appear to be the case or the large single-purpose parking decks, then yes, below grade is better than above grade for diminishing the physical affect that parking can have on urban environs.
The second concern relates to Pershing Square in LA, long-known as refuge for drunks and indigents (that is if you can find people at all). Pershing has gone thru several design and redesign processes to "give it life" for lack of a better term. But, like many design efforts here in Dallas, eschewing to acutely address the issue at a fundamental level, preferring instead for superficial treatments (shrub it up! Program it!).
Rule #1 - Truly successful urban parks require ZERO programming. They are successful merely as spaces, with the caveat that all of the other ingredients of urbanism adjoin that park.
So how did Pershing fail despite having pretty good urban context? Well, they never address the speed ramps on all four sides of the park. They might as well have put a moat with sharks or at least killer rabbits, with nasty sharp pointy teeth.
So, option 1: Give up on putting below grade parking under Main Street Gardens. It's running something like $40,000 per space these days for such construction. Do you think we're getting our bang for our tax buck? Me thinks not.
option 2: pay for it by carving out most of Pacific Plaza, the proposed park next to our office building here. This park is overscaled anyway and pinpoints my problem with the Parks masterplan. There was little to no strategic thinking about how to leverage development. If the City purchases the entire surface parking lot, seek a public-private partnership to develop say 60-80% of the site's acreage with urban mixed-use residential on a new, reduced and more effective park/public investment. I know, I know, that makes too much sense.
option 3: please for the love of gaud-i, think carefully about where the access to the subterranean garage is. me and my doggy don't want to traverse a sunken exit ramp to go to the "doggie run."
and you don't want to piss her off. SICK BLOGGER!