This is a combined list of the Spur (联络线), Parallel (并行线), Metropolitan Area Ring (都市圈环线) and City Ring (城市环线) routes of National Trunk Highway System Expressways of China. Auxiliary expressways are followed by two additional digits of their primary expressway and the GXX0X series routes are city beltways. Generally, odd-numbered routes have lower numbers in the east and higher numbers in the west; even-numbered routes have lower numbers in the north and higher numbers in the south.