When most people think of what can be accomplished in 4 minutes, running a mile isn't on the list of possibilities. On Friday, however, a dozen men capable of running a mile in 4 minutes or under will line up on Penn Avenue for the Liberty Mile road race, along with six women who can run the distance in 4:30 or faster. It is the strongest field in the history of the race, which Pittsburgh Marathon organizers first produced in 2012. “The only other place you're going to see a field of this caliber is going to be in the Olympic Trials,” P3R CEO Patrice Matamoros said.