The path to the Celestial City in JohnBunyan?'s Christian allegory, PilgrimsProgress?. As a pattern, StraightAndNarrowPath, is sort of like PrincipleOfLeastPrivilege combined with BigDesignUpFront. It says to follow the rules with devotion, and not to be tempted by the distractions on either side of the highway.
Bunyan's use derives from Matthew 7:14: "Because strait [is] the gate, and narrow [is] the way, which leadeth unto life, and few there be that find it."
Compare to SteerWithYourEyes; Contrast with the EightfoldPath.