CB TB PC
h
PCO QR l COQ COQ PCO COF SCO
= h =
=
= −
= × × ×Σ − − ×Σ ×
Σ
(1)
Where CB=reducing air pollution benefit;
TB= reducing air pollution benefit of transportations mode conversions;
PC = air pollution cost of power plant of urban rail traffic;
j COF = plant standard coal of j power plant of urban rail transit;
SCO = 2 CO emissions per standard coal;
PCO= emission price of 2 CO ;
QR = traffic flow rate of urban rail transit;
i h = modal choices for other transportations(1,2,3…m), and 1 h represents modal choice for the urban rail
transit;
i COQ = 2 CO emission by per person per km of i transportation modes, respectively; 1 COQ present
2 CO emission of per person per km of urban rail transit;
l = the average travel distance;
cn = quantity of urban transportation modes;