Figures (7)  Tables (4)

    • Figure 1. 

      Comparison of vehicle speed simulation and field data.

    • Figure 2. 

      Schematic diagram of the diversion area.

    • Figure 3. 

      Traffic operating conditions of low traffic volume. (a) Graph of speed and truck proportion, (b) Graph of delay and truck proportion.

    • Figure 4. 

      Traffic operating conditions of medium traffic volume. (a) Graph of speed and truck proportion, (b) Graph of delay and truck proportion.

    • Figure 5. 

      Traffic operating conditions of high traffic volume. (a) Graph of speed and truck proportion, (b) Graph of delay and truck proportion.

    • Figure 6. 

      Exit ramp flow vs truck length. Traffic volume: (a) low, (b) medium, and (c) high.

    • Figure 7. 

      Exit ramp flow vs truck platoon size. Traffic volume: (a) low, (b) medium, and (c) high.

    • Name Value
      Simulation length 1,000 m
      Maximum speed of the car 120 km/h
      Maximum speed for trucks 80 km/h
      Physical length of the car 7.5 m
      Physical length of the truck 15 m
      Regular acceleration of the car 2.5 m/s
      Regular acceleration of the truck 1.5 m/s
      Driver reaction time 0.8 s
      Probability of slowing down of the car-free driving 0.2
      Probability of slowing down of the truck free driving 0.1
      Probability of free lane-changing behavior 0.3
      Probability of mandatory lane-changing behavior 1
      Beginning of diverging area 500 m
      Regular deceleration of the car 4 m/s
      Regular deceleration of the truck 2.5 m/s

      Table 1. 

      Model parameters.

    • Lane type Lane-changing times Accuracy %
      Actual data Initial cell model simulation values Improved cell model simulation value
      Mandatory lane-changing behavior 1.353 1.657 1.415 95.62
      Free lane-changing behavior 0.152 0.125 0.176 86.36

      Table 2. 

      Simulation results of lane-changing times.

    • Lane type Initial cell model simulation values
      (veh/h)      		 Improved cell model simulation value (veh/h) Actual data (veh/h) Error rate
      Flow rate of the on-ramp
      Lane 1 1,589 1,477 1,430 3.18
      Lane 2 1,654 1,558 1,548 0.64%
      Lane 3 1,054 1,123 1,112 0.98
      Lane 4 956 1,048 1,029 1.81%
      Exit ramp − − −
      Flow rate of the exit ramp
      Lane 1 1,291 1,402 1,380 1.57%
      Lane 2 1,398 1,377 1,335 3.05%
      Lane 3 1,116 1,032 1,077 4.18%
      Lane 4 832 1,008 994 1.39%
      Exit ramp 387 439 426 2.96%

      Table 3. 

      Simulation results of hourly traffic volume.

    • Traffic volume (veh/h) The number of traffic conflicts
      No truck barrier (times) With truck barrier (times) Increase ratio
      Low traffic volume 14.1 17.4 23.4%
      Medium traffic volume 26.3 33.1 25.8%
      High traffic volume 40.2 53.2 32.3%

      Table 4. 

      Evaluation of traffic safety.