Toll road | EPFL Graph Search

A toll road, also known as a turnpike or tollway, is a public or private road (almost always a controlled-access highway in the present day) for which a fee (or toll) is assessed for passage. It is a form of road pricing typically implemented to help recoup the costs of road construction and maintenance. Toll roads have existed in some form since antiquity, with tolls levied on passing travelers on foot, wagon, or horseback; a practice that continued with the automobile, and many modern tollways charge fees for motor vehicles exclusively. The amount of the toll usually varies by vehicle type, weight, or number of axles, with freight trucks often charged higher rates than cars. Tolls are often collected at toll plazas, toll booths, toll houses, toll stations, toll bars, toll barriers, or toll gates. Some toll collection points are automatic, and the user deposits money in a machine which opens the gate once the correct toll has been paid. To cut costs and minimise time delay, many

A Dynamic Network Approach for Multimodal Urban Mobility

Nan Zheng

Recent advances in traffic flow theory at the network level, namely the Macroscopic Fundamental Diagram (MFD), reveals the existence of well-defined laws of congestion dynamics at aggregated levels. The same knowledge for multimodal networks however is limited. It is critical to understand how urban space can be allocated and managed for multimodality. The objective is to develop aggregated modeling and optimization approaches, which will contribute on the knowledge of congestion dynamics in cities of different structures and mode usages, and ultimately facilitate the design of efficient and equitable urban transport policies. Building on the knowledge of the single-mode MFD theory, a bi-modal MFD model considering the effect of mode conflict is proposed for mixed networks of buses and cars. A system-level model is developed for multiple-region city network. The flow dynamics among regions are described by a regional level flow conservation law. A non-linear optimization framework is performed to optimize space allocation, minimizing the total passenger cost, given certain demand, city structure and road facility. Then, parking limitation is integrated in the proposed multi-modal system model, where vehicles cruising for parking are also integrated. The extra delay of cruising is captured by a geometric distribution related to the time-dependent parking availability and estimated at the aggregated level. The delay cost to other users is also estimated via the bi-modal MFD, and it shows the effect of cruising on all travelers who do not require parking. Optimal parking pricing policies for on-street and garage parking are obtained through the optimization framework, as well. The existence of a three-dimensional MFD (3D-MFD) for mixed bi-modal networks is investigated and analyzed via micro-traffic simulation studies. A 3D-MFD relates vehicular production of a network (flow, travel distance) to the density of cars and buses, where the impact of each mode on network performance can be directly observed. To further compare the modal impact on performance, the Bus-Car Unit equivalent value is estimated, indicating that this value is state- and mode-composition dependent rather than deterministic. In addition to the conventional vehicle-flow-based analysis, a passenger 3D-MFD is derived which provides a different perspective of the flow characteristics in bi-modal networks. Simulation study on 3D-MFD based perimeter-control shows promising performance in real-time control. The final part of the thesis concerns the MFD-controlled congestion pricing. Feedback-type control mechanisms are proposed to determine and adjust the time-dependent tolls, based on congestion level as expressed by the MFD. One pricing scheme also considers userâs adaptation to the toll cost, allowing a great flexibility in toll adjustment, and deals with the promotion of public transport usage. The performance of the pricing schemes is investigated in an existing agent-based model where the complex travel behavior in real-life is reasonably reproduced. Results demonstrate that the pricing schemes are effective in congestion reduction. Remarkably, smooth behavioral equilibrium in long-term operation is found under such pricing schemes. Furthermore, user heterogeneity with respect to value-of-time is introduced in the agent-based model. By realizing and treating this heterogeneity, pricing strategies can achieve even higher efficiency and equitable benefit.

EPFL2014

Exploring potential benefits of bridge condition assessment in highway operations

Ian Smith

In recent years, an increasing number of private firms are involved in public works using the funding strategy of public-private partnerships (PPPs), especially for civil infrastructure projects such as highways and bridges. In this paper, a framework is proposed to quantify the potential benefits of condition assessment in the operation phase. The updated safety condition of highway bridges is introduced as a constraint of the profit optimization problem. The framework includes the following three steps. First, structural identification is carried out to identify parameter values of the bridge involved in the highway project. Then the reserve capacity under the relevant limit state is calculated based on the requirements of bridge design codes. The last step is to investigate the effects of reserve capacity on the optimal operating profit. This framework is applied to a highway flyover project in Singapore. The optimal operating profit based on quantified reserve capacity increases relative to the case without information of reserve capacity. This significant potential economic benefit associated with bridge condition assessment in the operation phase of toll highways.

IABSE2019

Optimizing the operating profit of young highways using updated bridge structural capacity

Ian Smith

As more private firms participate in public projects aiming to increase their profits by adjusting operational strategies, there has been an increasing demand for structural identification in the operational phase. In this paper, we propose a framework for finding the optimal profit of toll highways over a 5-year part of the operating period. Toll rates are adjusted using the updated safety condition of highway bridges as a constraint on the optimization task. The safety constraint explicitly reflects the requirement on the traffic volume based on the reserve capacity of bridges. The framework includes the following three steps. First, structural identification is carried out to identify parameter values of the bridge involved in the highway project. Then the reserve capacity under the relevant limit state is calculated based on the requirements of bridge design codes. The last step is to investigate the effects of reserve capacity on the optimal operating profit. This framework is applied to a highway flyover project in Singapore. The optimal operating profit based on quantified reserve capacity increases compared to the case without information about reserve capacity. Also, the finding shows that the optimal profit will increase with the increases in values for the reserve capacity until the safety constraint is no longer critical.

2020

A Dynamic Network Approach for Multimodal Urban Mobility

Nan Zheng

EPFL2014