[aaron38]

A lot of time in the burbs you have to look at the right of way on the roads. Dundee Road there is two lanes in each direction. Dundee is IL Highway 68. I'm willing to bet IDOT has right of way for 3 lanes each direction, plus extra turn lanes. Then there's the sidewalks.
It's the same way in burbs with Metra running through. Developments don't get to build right up to the tracks. They can only build up to the right of way, and that still gets padded.