Figures (5)  Tables (1)

    • Figure 1. 

      Examples of annual change of vehicle population in Tokyo, Japan (1906−2008) and road network area in Beijing, China (1996−2021). (a) Vehicle population. (b) Road network area.

    • Figure 2. 

      Dynamic evolution process of urban traffic system during 2020−2029. (a) Energy reserve. (b) Vehicle population. (c) Road network area. (d) Road network saturation. (e) Average vehicle speed. (f) GHG emissions.

    • Figure 3. 

      Dynamic evolution process of urban traffic system until it is stable. (a) Energy reserve. (b) Vehicle population. (c) Road network area. (d) Road network saturation. (e) Average vehicle speed. (f) GHG emissions.

    • Figure 4. 

      The relationship among GHG emissions, authorized vehicle proportion θ, average increment energy consumption a1, and minimal energy consumption a2. (a) GHG emissions under different θ and a1. (b) GHG emissions under different θ and a2. (c) GHG emissions under different a1 and a2. (d) θ* under different a1 and a2

    • Figure 5. 

      GHG emissions in the future under different authorized vehicle proportions θ. (a) At 10 years later. (b) At 40 years later.

    • Parameters/
      variables      		 Meanings Values
      Tmax Maximum cycle number 3,650−36,500
      r1 Energy growth rate 0.005
      r2 Vehicle scrapping rate 0.0007
      r3 Growth rate of road network area 0.0002
      a1 Average increment of energy consumption per vehicle 1 × 10−5, 2.5 × 10−4
      a2 Minimal energy consumption per vehicle 1 × 10−7, 1.5 × 10−5
      b Conversion coefficient 15
      b0 Coefficient of function of GHG emission factor 7.613534994965560
      b1 Coefficient of function of GHG emission factor −0.138565467462594
      b2 Coefficient of function of GHG emission factor 0.003915102063854
      b3 Coefficient of function of GHG emission factor −0.000049451361017
      b4 Coefficient of function of GHG emission factor 0.000000238630156
      c Increment coefficient 0.15
      d Decrement coefficient area 0.00001
      e Parking impact coefficient 0.0001
      K Maximal land area for building road network 100
      m Detour coefficient 1
      n Loading coefficient 0.63
      x0 Initial value of energy reserve 10
      y0 Initial value of vehicle population 640.7474 × 104 veh
      z0 Initial value of road network area 90.24696 km2
      $ \theta $ Authorized vehicle proportion [0.5, 1]
      $ \Delta \theta $ Calculation interval of $ \theta $ 0.001
      $ \Delta {a}_{1} $ Calculation interval of a1 1 × 10−7
      $ \Delta {a}_{2} $ Calculation interval of a2 1 × 10−7

      Table 1. 

      Numerical settings.