Optimum Location of Motorway Interchanges: Concessionaires’

Perspective

PhD student Hugo RepolhoUniversity of Coimbra PORTUGAL

Introduction (1)

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OBJECTIVE: develop an optimization model for assisting toll-motorway concessionaires inthe analysis of the most profitable solutions for Motorway Interchanges Location Problem.

The location of the interchanges strongly impacts the amount of traffic that the motorwaycan capture from the existing road network.

In Europe most motorways are owned by the State but operated by private concessionaires.

The concessionaires may define certain design details for the motorway, namely themotorway interchanges location (access and exit points).

Their profit comes from the application of a certain toll fee per mile to the motorway users.

Introduction (2)

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ASSUMPTIONS:

There are two types of routes to consider:

1. Routes through the existing road network (choice 1);2. Routes through a combination of existing roadway segments and new motorway

segments (choice 2).

• People will travel through the least cost route;

• The proportion of people using the motorway increases as the travel costs decrease;

Choice 1Choice 2

MILM: model’s objective function

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OBJECTIVE FUNCTION: expresses the profit for the concessionaire, given as thedifference between total toll fee revenue and fixed charges for installing and operatingthe interchanges and constructing the motorway.

Total toll fee revenue Fixed charges

The MILM can be seen as a particular case of the p-hub median problem, which wasformulated by Campbell, 1994.

Portuguese case study

•Motorway A25 located in the center of Portugal•Dataset : 55 centers and 33 candidate motorway interchanges;

ArcMap 9.2 Image

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Portuguese case study - Results

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13

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1318 2624

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1014 15 17

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49081

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32250

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30873 31369

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0.03 0.04 0.045 0.049 0.05 0.051 0.053 0.054 0.055 0.056 0.06 0.065 0.07 0.08 0.085 0.09 0.1

Pro

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Toll fee (€/km)

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•The model was run for several Toll fee values.

Final Considerations

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pectiveThe optimum location of motorway interchanges under the concessionaires’

perspective follows a previous work done under the users’ perspective, whichaimed to minimize travel costs.

We believe that the concessionaires’ perspective is the most relevant in real-world applications.

The models presented are useful in toll-motorway concessionaires’ cost-benefitanalysis.

Users’ Perspective…

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