That may be true, but on the flip side that is also a reason why density outside of the Boston core falls off a cliff. Cities in the Northeast have denser cores but have much, much lower density suburbs. The core that Boston has is irreplaceable but the lack of more even density on the fringes and outside of 128 means that the net effect and cost to society is likely comparable -- as is evidenced by the poorly maintained infrastructure across the entire region.
Omaja -- the density in the inner, outer and exurbs is a result of early history
In most of the country the cities were seeded on a lake, river, rail line and then they grew into wildernerss or sometimes large farms and ranches -- but in either case outside the cities you had unincorporated territory -- within a county boundary -- buth that's it -- much of Texas is still like that -- e.g. about 3 miles west of where I used to live in Austin Texas was the City Line -- if you headed west from there aside from some resorts on Lake Travis, small towns and a few small cities fairly close to Austin (e.g. Fredricksburg) -- you will not hit another significant size city until you reach El Paso 400 miles away -- similarly go east and nothing much until you hit Houston 200 miles away
The reason is that as development occured in unincorporated areas - the existing cities used their powers of annexation to incorporate the developments into the city limits
In contrast in the Northeast in general and New England in specific -- settlement was very very rapid -- almost Big Biang style explosive spreading out from the point of contact -- e.g. Plymouth filled the county in a decade or two, -- simiarlly with Boston and Cambridge, Salem and Newburry Port and within a decade or three you had a map of incorporated towns -- approximately one 1/2 days walk or so apppart on the rudiments of what would become Lexington-Waltham St, Lexington-woburn St., etc.
fromthe Wiki article
http://en.wikipedia.org/wiki/Lexington,_Massachusetts
"...Lexington was first settled circa 1642 as part of Cambridge, Massachusetts. What is now Lexington was then incorporated as a parish, called Cambridge Farms, in 1691. This allowed them to have a separate church and minister, but were still under jurisdiction of the Town of Cambridge. Lexington was incorporated as a separate town in 1713. It was then that it got the name Lexington..."
Just to the east of Lexington -- Arlington was settled as a village called Menotomy in 1635 again as part of Cambridge, Massachusetts. Nearly 200 years later, Menotomy and additional land which later became the town of Belmont, and some land from Charletown was incorporated on February 27, 1807 as West Cambridge -- -later to be renamed Arlington after the Civil War National Cemetary.
Land to the west of Lexington -- today's Bedford had been granted to John Wintrop first Governor of the Massachusetts Bay in 1637 -- setlement began on this land in 1640
Further west of Bedford -- Concord was settled even earlier in 1635 when some of the original English settlers purchased land from an Indian tribe
So in the 30 years after the founding of Boston there were people farming and living nearly 20 miles west of the original setltlement site -- by the time Boston was 100 years old and still confined by its original geography -- incorporated towns with their own governmnts nearly surrounded Boston
of course later some of these communities would be annexed by Boston (Hyde Park, Dorcheter, Roxbury, Charlestown) -- but equally well establised citees such as Quincy and Cambridge would not be anexed and would force Boston to stop growing out
In the mid 19 th Century when the railroad and then in the late 19 Century when street car lines grew out from Boston they together served as the arteries of the first commuter suburbs -- collecting people living along the tracks and most importantly around the town centers where the commuter rail stations were located. Where there weren't any tracks -- farms persisted until the 2nd half of the 20th century when cars and the web of roads freed people from having to live next to rails -- then Zip, Zoom in another decade or two all the farms got subdivided into the suburban sprawl 1/2 acre single family housing + low density shops and office parks.
Some redensification has occured with the recent 2nd (and 3rd gen in some cases) redevelopment of the original 1 story indistrial parks built along and near to RT-128 (e.g. Nordblom original NW Park in Burlington) and some has happened in Lexington Center and the other town centers in the area.
So now just inside and outside of Rt-128 we have a mostly radial and some crcumferential pattern of clumped development with some density superimposed on a mostly low density suburban background
However a lot of this development in the Lexington area is not particularly close to existing rail ROW -- making doing much about it -- somewhat problematical
