Thanks to Friends of the Riverfront for alerting us to this:

“Please be advised that a portion of the Three Rivers Heritage Trail along the North Shore will be temporarily detoured from February 1st to April 1st 2011. The detour is necessary to repair and replace deteriorated surface concrete on the trail in front of PNC Park. Please see below for a map of the trail detour or for additional information and project updates visit the Sports & Exhibition Authority. We appreciate your cooperation and understanding of this inconvenience to accomplish this maintenance activity.”
View Riverwalk Detour Route