Multiple‐Factor Influence on Air Quality of Road Motor Vehicles Tail Number Limit in Administrative Area of Beijing, China

Table 1

Impact factors of air quality.

Number	Impact factor	Effect
1	Time-year	Periodic change, overall decline
2	Time-month	Cyclic change
3	Time-day	Cyclic change
4	Time	Fluctuations
5	Weather	Classification change
6	Industrial emissions	Linear relationship
7	Opportunity cars	Linear
8	Oil and gas quality	Inverse function
9	PM2.5	Partially positive
10	PM10	Partially positive
11	SO2	Partially positive
12	CO	Partially positive
13	NO2	Partially positive
14	O3_8 h	Partially positive