Keith Bunin’s The Coast Starlight is one of those “ship of fools” dramas that throw together unacquainted travelers on a common carrier. The title comes from a real passenger-train service running daily from Los Angeles to Seattle. Amtrak’s website promises potential Coast Starlight customers a “grand West Coast train adventure … pass[ing] through Santa Barbara, the San Francisco Bay Area, Sacramento, and Portland.” For Bunin’s characters, however, the reality is not so much an adventure as an anxious long-haul.