Calculating the Contribution Rate of Intelligent Transportation System in Improving Urban Traffic Smooth Based on Advanced DID Model

Table 4

Correlation between indicators.

Probability	Correlation
	ASPD	GDP	POP	CVECH	RODM	RODA	PVECH	PPER
ASPD	1.000	0.748	0.703	0.727	0.805	0.830	0.826	0.704
	—	0.008	0.016	0.011	0.003	0.002	0.002	0.016
GDP	0.748	1.000	0.982	0.992	0.967	0.929	0.893	0.828
	0.008	—	0.000	0.000	0.000	0.000	0.000	0.002
POP	0.703	0.982	1.000	0.995	0.934	0.888	0.851	0.822
	0.016	0.000	—	0.000	0.000	0.000	0.001	0.002
CVECH	0.727	0.992	0.995	1.000	0.955	0.905	0.867	0.832
	0.011	0.000	0.000	—	0.000	0.000	0.001	0.002
RODM	0.805	0.967	0.934	0.955	1.000	0.956	0.916	0.827
	0.003	0.000	0.000	0.000	—	0.000	0.000	0.002
RODA	0.830	0.929	0.888	0.905	0.956	1.000	0.937	0.824
	0.002	0.000	0.000	0.000	0.000	—	0.000	0.002
PVECH	0.826	0.893	0.851	0.867	0.916	0.937	1.000	0.800
	0.002	0.000	0.001	0.001	0.000	0.000	—	0.003
PPER	0.704	0.828	0.822	0.832	0.827	0.824	0.800	1.000
	0.016	0.002	0.002	0.002	0.002	0.002	0.003	—