A fascinating maze of trackage outside Chicago Union Station is about to be negotiated by an outbound Metra commuter train on April 17, 2009.

An outbound Metra commuter train negotiates the maze of trackage leading from Chicago Union Station on April 17, 2009.

METX 103 and 85 are in charge of an outbound express through Franklin Park during the evening rush.

An old metra F40 brings the 915 outbound set through downtown lemont approaching his station stop.

A double header of Metra F40's shove an inbound commuter train through CP Morgan and towards Chicago Union Station during the afternoon rush hour.

METX 103 leads an outbound to Elgin as YPRCP pulls onto the CP.

Metra F40PH-3 #103 leads an outbound train, Metra F40PH-3 #106 shoves an inbound train, and an Amtrak Hiawatha is seen in the distance during the busy afternoon rush hour in Chicago at CP Morgan, ... (more)

Outbound North Central train to Antioch makes station stop at River Grove. North Central trains to Antioch use Milwaukee West line from Chicago Union Station to Franklin Park where they diverge ... (more)

Metra 103 makes a station stop at the temporary platform in Joliet with the first heritage corridor train of the evening.

Metra 103 leans through the curve as it leads an afternoon rush train through Elmwood Park

Metra 103 leads a Southwest Service train past the Amtrak Shops as they bring commuters towards their homes in Oak Lawn and Manhattan.

One of Metra / RTA's original F40PHs is staged outside of Union Station for the afternoon rush.

Heading toward town with another slug of commuters, Metra 103 heads over a bascule bridge over the north branch of the Chicago River, just north of the Armitage station.