TH: Spring Songs

In response to Richard's post about the wonders of Jack Hammers in
the city (especially on a spring eve):
Here in Baltimore, residents interested in trees and other
naturally green units, must constantly deal with a plethora of
concrete and asphalt.  Recently, I discovered (from my co-worker,
Patricia) that in Washington DC, it is illegal to fill in a tree
pit (tree well).  How about that?  Wouldn't our lives be sweeter if
places (spaces) to plant trees were forever (ad infinitum)
protected by law?
Could anybody out there tell us what the situation is in their
city?  Certainly, we are not the only ones suffering at the hands
of artificial infra-structure...  How do other cities deal with
this conflict?
All comments and information welcome!
 Here in the modern inner-city, there is no sound which reminds
 us more of the joys and promise of springtime than the sing-
 song chatter of jackhammers, crunching up the sidewalks and
 making way for new street trees!  How we love to wake up to it!
 In Baltimore, trees are spaced at minimum intervals of 20 feet
 (~8m), which is approximated by centering them in front of every
 2nd rowhouse (the commonest dwelling unit).  Tree pits are tra-
 ditionally about 4 feet square (~1.5m).  When we can, we try
 to increase the area of these older pits.  Oftentimes pits are
 cut smaller, however, because the dimensions of a single block
 of sidewalk concrete are typically under 4 feet.
 Gary and I have often discussed strategies for giving those poor
 trees some more breathing space.  We would like to simply join
 all the pits into one long one.  Heck, we'd like to replace *all*
 the concrete with recycled brick and block, loosely fitted in
 Another idea is to cut mini-pits in front of the odd houses, be-
 tween the trees.  Those folks could then enjoy a little slice of
 nature in front of their own homes, the trees would fair better,
 and area drainage would improve, helping out the local streams.
 Delirious with Spring Jackhammer Fever (SJF),
Zone 7