What does the prefix M of Shenzhen bus mean?

I searched for it for a long time and finally found it. I taught myself, hehe.

Public transport in Shenzhen

Trunk line (starting with m)

The trunk line adopts "linear" transportation mode, that is, it stops at all or most stations along the line to realize the distributed transportation mode of passenger flow along the line, mainly providing distributed services along the line for urban passenger flow corridors and traffic trunk lines, ensuring large-volume transportation for urban passenger flow corridors, and providing medium-speed transportation services for medium-distance passengers between adjacent groups in the city;

Other prefixes

J: sightseeing route

K: express train

B: branch line (long-distance line)

N: night bus

E: express delivery

The E, M and B lines have been in service since 2009.

The following is the news of 2009- 12-22.

The development goal of Shenzhen bus network is to establish an integrated bus network with clear functions, clear levels and reasonable structure, comprehensively sort out and further optimize the bus network structure in the special zone according to the functions of the three-level bus network, improve the bus network coverage outside the special zone, and meet the travel needs of citizens.

The three-tier bus network includes three types: express line (beginning with E), trunk line (beginning with M) and branch line (beginning with B). Express line adopts "point" transportation mode, that is, between two points or limited stops, it realizes long-distance direct transportation mode, mainly providing fast transportation service for inter-group and inter-group passenger flow in the city; The trunk line adopts "linear" transportation mode, that is, it stops at all or most stations along the line to realize the distributed transportation mode of passenger flow along the line, mainly providing distributed services along the line for urban passenger flow corridors and traffic trunk lines, ensuring large-volume transportation for urban passenger flow corridors, and providing medium-speed transportation services for medium-distance passengers between adjacent groups in the city; The feeder line also adopts "linear" transportation mode, which mainly provides distribution services along the way for the city's sub-branch network, and at the same time provides passenger flow connection and feed-in services for the upper bus networks such as tracks, express lines and trunk lines.