4.2. Convergence test
Figure 3 shows the transition of PT volumes as accordance with the iteration. Note that the number of iterations
here is the sum of the inner and outer loop of the solution algorithm. The reason why the PT volume does not transit
continuously is that the travel time of PT network is updated by the result of link flows of PC network at the begging
of the outer loop. (In this case, the calculation finishes after 8 times of outer iterations.) As the number of iterations
increases, PT volume converges to around 8,800. Also, PT volume at the end of inner loop becomes closer as the
number of outer loop becomes larger. Therefore, we can confirm that the proposed model reaches to the
convergence point.