“Two Trains Running” plays at the Oregon Shakespeare Festival in Ashland tonight, and it’s well worth the three hours and 15 minutes you’ll spend with Memphis, Wolf, Risa, Hambone, Holloway and Sterling. The August Wilson play is set in a 1969 Pittsburgh diner, where owner Memphis Lee is fighting the city’s efforts to take over his joint by eminent domain to make room for a housing project. The characters — and the sound of waitress Risa’s shoes flap-flap-flapping slowly against the floor — will stay with you long after the curtain falls. Visit www.osfashland.org for ticket information. The show starts at 8 tonight.