ONE OF THE FUN THINGS about the second- and third-tier seating at the Winningstad Theatre is that you can watch other people watch the performance. At the Portland Playhouse's production of Jitney, as my friend said at the intermission, "I like sitting up here, because you can see how many people are crying."

Jitney, part of August Wilson's Century Cycle, could hardly be called a sad play. It has its share of darkness, but it recalls that favorite Wilson quote of motivational Tumblrs, "Confront the dark parts of yourself, and work to banish them with illumination and forgiveness."

The play takes place in a 1970s taxi station in Pittsburgh, where most of the characters drive unlicensed taxicabs, or "jitneys." Characters come in and out of scenes as their trips allow and interrupt lines of dialogue to answer the phone, "Car service." Wrick Jones as the sad, drunken clown Fielding and Victor Mack as hotheaded gossip Turnbo make especially great comedic use of that line, each unfailingly answering in his own specific sing-song, even if a moment before he was shouting or crying.

Illumination is Wilson's mode in the Century Cycle, and director G. Valmont Thomas' production for Portland Playhouse is generous with forgiveness. The characters in Jitney are defined by various qualities: the boss, Becker, is warm and supportive of his employees; Doub is often the only voice of reason; Youngblood is ambitious and cocky; Turnbo is loud and aggressive; and Fielding is a drunk so drunk even his saddest stories are funny.

What unites these characters is numbness to their own darkness. An unwillingness to see or understand some loss has left each incapable of illumination. Even Doub, played with indomitable patience and intelligence by Mujahid Abdul-Rashid, recounts the story of how he became numb to darkness, cleaning up battlefields in the Korean War.

Rodney Hicks and Ashley Williams play the youngest characters, Youngblood and his wife, Rena, with verve, eyes lit with youthful anger and sex. But it's Kevin Kenerly's Becker and Vin Shambry's Booster, "Becker's boy," whose relationship provides the most intensity and tragedy. Becker's warmth at work is at odds with his coldness to his son, and Kenerly plays the pain of that duality with sobering clarity. Shambry's Booster, meanwhile, can't come to terms with his own violent past or understand his father's treatment of him. Their best, most brutal scene together is the one that might bring you to tears.

In the end, though, Portland Playhouse's Jitney takes that old line about illumination and forgiveness as a mandate, and the company explores the play's darkness with light and warmth.