Figures (5)  Tables (6)

    • Figure 1. 

      Logical diagram of the tripartite evolutionary game model.

    • Figure 2. 

      System evolution trends under different policy scenarios.

    • Figure 3. 

      Agent grid evolution under the experience-driven mode.

    • Figure 4. 

      Agent grid evolution under the adaptive learning mode.

    • Figure 5. 

      Correlation trend under different scenarios.

    • Parameter Definition Description and practical significance
      $ {C}_{P} $ Additional costs of port green transformation Investments made by ports in green hub retrofitting and low-carbon facility
      construction to enhance collaborative efficiency
      $ C_S $ Additional costs of river-sea intermodal transformation Additional collaborative costs incurred by intermodal operators in information
      system integration and multimodal transport organization
      $ {C}_{R} $ Additional costs of road transport transformation Equipment renewal costs incurred during the transition of road transport
      from conventional diesel-powered trucks to green energy vehicles
      $ {G}_{s} $ Guiding policy subsidies Phased incentives provided by the government to encourage agents to
      choose green transformation, aimed at offsetting transition costs
      $ {T}_{c} $ Carbon tax constraint costs Punitive environmental taxes levied on the road transport sector that persists in
      traditional high-emission modes, increasing evolutionary resistance
      $ {R}_{i} $ Baseline operating revenue Benchmark market revenue for the three types of agents ($ i\in \left\{P,S,R\right\} $) when
      maintaining the status quo without adopting collaborative transformation
      $ {R}_{c} $ Green collaborative incremental revenue Incremental profits generated by system structural optimisation and efficiency
      improvement when the three agents reach a collaborative consensus
      $ {L}_{i} $ Collaborative failure losses Efficiency losses or congestion costs resulting from the lack of coordination
      within the collection-distribution system ($ i\in \left\{P,S,R\right\} $)

      Table 1. 

      Notations and definitions for the multi-agent model.

    • Parameter category Symbol Definition Scenario 1 Scenario 2 Scenario 3
      Variable parameters $ {C}_{P} $ Additional costs of port green transformation 15 20 15
      $ C_S $ Additional costs of river-sea intermodal transformation 60 25 40
      $ {C}_{R} $ Additional costs of road transport transformation 60 25 40
      $ {T}_{c} $ Carbon tax constraint costs 15 20 15
      $ {G}_{s} $ Guiding policy subsidies 4 25 40
      $ {L}_{i} $ Collaborative failure losses 20 15 60
      Fixed parameters $ {R}_{c} $ Green collaborative incremental revenue 55 55 55
      $ {R}_{i} $ Baseline operating revenue 80 80 80

      Table 2. 

      Simulation parameter assignments.

    • Environmental state $ s_{i}^{t} $Port (C, T)River–Sea intermodal (C, T)Road transport (C, T)
      (0,0)135851383112456
      (0,1)10718111924914668
      (0,2)30412624425776168
      (1,0)1161533512914791
      (1,1)302164270152326131
      (1,2)307276274215327135
      (2,0)17260016145259
      (2,1)275288276188329275
      (2,2)308288276259332300
      The bold values are the steady Q-values.

      Table 3. 

      Steady-state Q-values under the low subsidy, low carbon tax scenario.

    • Environmental state $ s_{i}^{t} $Port (C, T)River–sea intermodal (C, T)Road transport (C, T)
      (0,0)11113123671268
      (0,1)6421916812251182
      (0,2)10224010321861206
      (1,0)23212182143307107
      (1,1)311220151239333153
      (1,2)334269303219334186
      (2,0)2151211778259178
      (2,1)334228119290332217
      (2,2)337321306296341308
      The bold values are the steady Q-values.

      Table 4. 

      Steady-state Q-values under the low subsidy, high carbon tax scenario.

    • Environmental state $ s_{i}^{t} $Port (C, T)River–sea intermodal (C, T)Road transport (C, T)
      (0,0)403026658
      (0,1)021331027135188
      (0,2)5955233513171320
      (1,0)332275074466160
      (1,1)60611973308605214
      (1,2)608556336307620451
      (2,0)0352790615211
      (2,1)384557334256621492
      (2,2)621563336317621537
      The bold values are the steady Q-values.

      Table 5. 

      Steady-state Q-values under the high subsidy, low carbon tax scenario.

    • Environmental state $ s_{i}^{t} $Port (C, T)River–sea intermodal (C, T)Road transport (C, T)
      (0,0)36996533360203
      (0,1)713903612060322
      (0,2)5680027060421
      (1,0)279387354156148358
      (1,1)596349369281317568
      (1,2)532565375303621418
      (2,0)584328190328374574
      (2,1)613557370345626576
      (2,2)618575377371633588
      The bold values are the steady Q-values.

      Table 6. 

      Steady-state Q-values under the high subsidy, high carbon tax scenario.