The 'National Standard of the People's Republic of China - GB5768 (Road Traffic Signs and Markings)' provides a clear explanation of yellow grid lines: it specifies that they are road markings used to inform drivers that temporary parking is prohibited at intersections (or other entrances and exits) where these markings are installed, in order to prevent traffic congestion. They are painted at intersections or other entrances and exits where temporary parking is prone to occur, depending on the specific situation. Road traffic markings are categorized as follows: a) White dashed lines, when painted on road sections, are used to separate traffic flows moving in the same direction or as safety distance recognition lines; when painted at intersections, they guide vehicle movement. b) White solid lines, when painted on road sections, separate motor vehicles from non-motor vehicles moving in the same direction or indicate the edge of the roadway; at intersections, they can serve as guide lane lines or stop lines. c) Yellow dashed lines, when painted on road sections, separate opposing traffic flows. When painted on the roadside or curbs, they prohibit long-term parking on the roadside. d) Yellow solid lines, when painted on road sections, separate opposing traffic flows; when painted on the roadside or curbs, they prohibit long-term or temporary parking on the roadside. e) Double white dashed lines at intersections serve as yield lines; on road sections, they indicate variable lane lines that change direction over time. f) Double yellow solid lines on road sections separate opposing traffic flows. g) Yellow solid and dashed lines on road sections separate opposing traffic flows. On the side with the yellow solid line, vehicles are prohibited from overtaking, crossing, or turning; on the side with the yellow dashed line, overtaking, crossing, or turning is permitted if safe. h) Double white solid lines at intersections serve as stop lines.
