Alternative Model to Determine the Optimal Government Subsidies in Construction Stage of PPP Rail Transit Projects under Dynamic Uncertainties

Table 3

Unit social cost of various modes of transportation.

Transport (yuan/person • km)	Bus	Bicycle	Taxi	Subway	Light rail
Own costs	0.144	0.0105	0.393	0.375	0.125
Road occupancy costs	0.01	0.061	0.11	0	0
Parking costs	0.00736	0.0526	0.0092	0	0
Traffic accident damage costs	0.0012	0.006	0.007	≈0	≈0
Environmental costs	0.121	0	0.175	0.00966	0.0126
Time value	0.867	1.079	0.325	0.325	0.325
Summation	1.151	1.209	1.019	0.71	0.463

Source: [49, 50].