Chicago skyline - mushrooms?

[Crusoe]

I've just returned from Chicago, and have one question: what are the "mushroom" shaped towers dotted alongside the main roads? My guess is that they might be mobile phone masts, but my mates disagree.

[Una Persson]

If they were between 20 to 45 meters tall they were almost certainly mobile phone towers.

[MikeG]

Well I can't say as I remember them but perhaps I've just blocked them out. I'll look for them when I go down to Lincoln Park Zoo today.
Where did you see them?

[Crusoe]

They were every couple of miles or so alongside the only roads I used (the interstates between Lisle and O'Hare). About 20-40 meters tall sounds about right.

[Whack-a-Mole]

Mobile phone towers are (usually) a basic, plain, iron girder affair. Usually they are wider at the base and taper to a point but not always. The real giveaway are the triangle antennas. Space up the tower are triangle 'platforms' with vertical antennas spaced around them...maybe three or four to a side.

Ugly things.

You'll also see cell antennas plastered to nearly anything rising off the ground...chimneys, water towers, sides of buildings, you name it.

[BrothaTJ]

Matt, how far off the road were they and how frequently did you see them? And how tall were they? I assume you were on I-88 (East-West Tollway) and I-294 (Tri-State Tollway). I can't picture what you're describing along those roads.