It is quicker and cheaper to prebook a town car or limo to get from the airport to downtown. Some taxi drivers charge up to $80 while a town car costs only $55.
Nightstar limos is a good one. www.nightstarlimo.com
Updates
Yeap, definitely much better idea. I use Stretch Limousine, Inc in Chicago (stretchlimochicago.com) on a regular basis for my limo trips between Chicago airport (such as Ohare midway) and multiple hotels in downtown Chicago.
Is this your business?
windycitylimos.com