Time-dependent road network design frameworks with land use consideration: policy implications

Abstract

In the past, transport network design focused on the effect of designs on the transport system alone but not on the land use system, and ignored the land use-transport interaction over time. This may result in obtaining suboptimal designs. Additionally, the impacts of road network improvement policies on the land use system, especially the benefit of landowners cannot be evaluated without considering the interaction. With these considerations, this paper proposes optimization frameworks for road network design considering the land-use transport interaction over time. Unlike existing models, the optimization frameworks can determine the optimal designs automatically without trial-and-error once the objective(s) is/are clearly defined. Moreover, these frameworks allow the evaluation of the impacts of the optimal designs on the related parties including landowners, toll road operators, transit operators, and road users, and help network planners and profit-makers with decision-making by eliminating many alternative designs. A numerical study is set up to examine road network design?s effects on these related parties under three road network improvement schemes: exact cost recovery, build-operatetransfer, and cross-subsidization (using the increase in transit profit to subsidize road improvement projects). The results show that the changes in landowner profits are not the same after implementing any scheme. These unequal changes raise the issue of the landowner equity. If the government guarantees the occurrence of this equity without providing any subsidy, societal benefit can decrease and the road network can become more congested. This implies that the government has to consider tradeoffs between parties? objectives carefully.