The north side plus some of the west side and NW is more urban than Boston (and San Fran). Chicago in area is a lot bigger though so it really depends on where you're talking about. The above statement of mine is true, but there are definitely neighborhoods on the south side that are much less urban (they used to be a lot more urban back in the day though).
I see a lot of people talking about the "wide roads of Chicago" and this is mainly untrue. The areas where it is wider than Boston are the main roads. If you actually get into the real residential sections of Chicago say in Lincoln Park or Lakeview, the roads are not very wide. We are not talking about European style here, but we aren't talking about wide avenues either. They are usually one land with available parking on the side (tightish slow driving). From my experiences with most of Boston..it's really not terribly different. There are plenty of wide avenues in Boston too and there are plenty of half way narrow residential streets.
Here is what the
real Chicago looks like in the residential areas of the north side neighborhoods:
http://goo.gl/maps/UxfEI
http://goo.gl/maps/CkDMg(7.5 miles from the "Urban Core")
Just for people unfamiliar with Chicago, I am going to list a bunch of community areas (basically neighborhoods) of Chicago that form one continuous geographical area just to show you the density of the north/part of west/NW sides of town. Keep in mind that Boston has 625,087 people for an area of 48.43 sq miles.
* Loop - Population: 29,283 | Area: 1.58 sq miles
* Near North Side - Population: 80,484 | Area: 2.72 sq miles
* Lincoln Park - Population: 64,116 | Area: 3.19 sq miles
* Lake View - Population: 94,368 | Area: 3.16 sq miles
* Avondale - Population: 39,262 | Area: 2 sq miles
* North Center - Population: 31,867 | Area: 2.07 sq miles
* Uptown - Population: 56,326 | Area: 2.35 sq miles
* Lincoln Square - Population: 39,493 | Area: 2.57 sq miles
* Edgewater - Population: 56,521 | Area: 1.71 sq miles
* Rogers Park - Population: 54,911 | Area: 1.85 sq miles
* West Ridge - Population: 71,942 | Area: 3.53 sq miles
Total Population: 618,573
Total Area: 26.72
Basically, around the same population of the entire Boston city is located within these 11 community areas (neighborhoods) of Chicago, but in 21.71 fewer square miles. Since it's 6500 less people in the area above, it might be closer to say 21 sq miles, not 21.71 sq miles fewer.
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