Research Article
Metamodel-Based Optimization Method for Traffic Network Signal Design under Stochastic Demand
Table 4
Computation time and optimal solution with initial points (0.8, 0.2, 0.8, and 0.2).
| Method | Computation time (s) | Improvement factor (iteration) | Total travel cost (veh/h) | Increase in total travel cost (%) |
| The original problem under stochastic demand | 9.6482 | 2008.76 | ā | Physical metamodel | 0.8985 | 10.73 (5) | 2052.92 | 2.20 | Combined metamodel method with model bias | 0.7878 | 12.25 (5) | 2013.18 | 0.22 | Gradient-based metamodel | 1.9916 | 4.84 (11) | 2010.57 | 0.09 |
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