Amazingly, Texas-raised troubadour and outlaw country badass Steve Earle has never made a blues record. Named for the car that inspired Robert Johnson’s classic “Terraplane Blues,” his latest disc with the ever-versatile Dukes taps into a rich well of inspiration that conjures flashes of Lightnin’ Hopkins and Willie Dixon, while holding close to Earle’s natural penchant for vivid, colorful and, at times, harrowing stories. Recent tribulations, including a messy divorce, provide some fodder for reflection (the ballad “Better Off Alone” is the standout), but overall, Earle sounds downright happy when he’s singing or shouting the blues, from the Faustian bargain he intones on “The Tennessee Kid” (with duly cranked guitar solos) to his wistful musings on the barrelhouse shuffle “You’re the Best Lover That I Ever Had.” Customized by the Dukes’ rich sonic palette, which shifts between country, swing, blues-rock and bluegrass, Terraplane is a well-oiled, road-worthy blues machine that puts the pedal to the mettle (and we do mean mettle).