72791 - Traffic Engineering M

Learning outcomes

The course deals will the analysis of transport networks and their performances due to the interactions among the several transport elements. Transport systems are the results of the interactions among several elements that affect one another both in both direct and indirect ways. The course wants to provide students with specific knowledge on the simulation, analysis and planning of transport systems by modeling transport demand and transport supply.

Course contents

The concept of transportation system: supply and demand subsystems, demand-supply interaction

Supply model: graphs, cost functions and transportation network; topological and mathematical representation of the supply model; link and path costs

Transportation demand model: transportation demand and main space-time characteristics; demand elasticity; link flow and path concepts; random utility theory; Logit, Nested-Logit, Probit models and their properties; stage demand model: Submodels of emission, distribution, modal choice and path choice; C-Logit model; calibration and validation of a demand model; likelihood function and validation tests.

Assignment models: Formalization and classification of assignment models; search for minimum cost paths on a transportation network; network load assignment with deterministic and stochastic path choice models; equilibrium assignment problems: Deterministic User Equilibrium (DUE) - Stochastic User Equilibrium (SUE); conditions of existence and uniqueness; algorithms solving DUE and SUE assignment problems

Direct transportation demand estimation: sample surveys; RP and SP data; sample estimation and confidence limits; correction of an initial transport demand estimation by using traffic flow counts; formulation of the demand estimation problem from traffic flows under different assumptions; choice of counting links

Supply model of transit systems: Characteristics of the transit systems; representation of the network for frequency or timetable transit systems; hyperpaths

Optimization models: simulation (what if) vs planning (what to) approaches; objective function, constraints and variables of optimization models; examples of objective functions

Innovative transport systems: Connected Automated/Autonomous Vehicles, MaaS, shared mobility

Notes on freight transport: intermodal and logistic centres - management of loading/unloading/stacking areas- handling equipment

Exercises: the exercises will cover the application of the different methods/models illustrated during the course. Depending on the conditions, the application of the different methods/models can be applied to design test cases: suitable information will be given at the beginning of the course.

Readings/Bibliography

Apart from lesson notes autonomously written by students, the following books are suggested:

Cascetta E. (2001) “Transportation systems engineering: theory and methods”, Kluwer Academic Press, Dordrecht, The Netherlands.

Di Gangi M., Postorino M.N. (2005) "Modelli e procedure per l'analisi dei sistemi di trasporto : esercizi ed applicazioni", FrancoAngeli, Italia.

 

Teaching methods

Expected: Lectures and Practical / Workshops (also blended, according to Covid situation)

Assessment methods

Written test made by theoretical and practical questions. Questions will concern the course contents, as described in the detailed program. The goal of the written test is to evaluate students’ knowledge and their ability to apply such knowledge in a working environment by using a system approach able to link the functional design of a single transport element to the transport network analysis and the produced effects.

Depending on the conditions, the written test may be replaced by a remote oral test with the same purpose.

Teaching tools

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Office hours

See the website of Maria Nadia Postorino