What does a solid white line on the right edge of the road (the right edge line) indicate?

WHITE EDGE LINE (RIGHT EDGE LINE): A solid white line running parallel to the road on the right side marks the boundary between the travel lane and the shoulder. Key rules: DO NOT DRIVE ON THE RIGHT SIDE OF THIS LINE except for emergency stops or specifically designated right turns; the edge line helps drivers stay in their lane in poor visibility (rain, fog, night); BIKE LANES are separated from the travel lane by a solid white line, but will also have 'BIKE LANE' text or a bicycle symbol; RUMBLE STRIPS are often placed near or at the edge line — feeling vibration means you're drifting off the roadway; SHOULDER: The area beyond the edge line is the shoulder — not a travel lane (except in specific HOV or emergency-only shoulder use designations during peak hours on some highways).