Francesco Ciaffi
, Ernesto Cipriani
, Marco Petrelli
, Rasa UšpalytėVitkūnienė
A new methodology for the public transport network design
Conference Information: 
9th International Conference on Environmental
Engineering, MAY 2224, 2014 Vilnius, LITHUANIA 
Source: 
ICEE2014  International Conference on Environmental
Engineering 
Book Series: 
International Conference on Environmental Engineering
(ICEE) Selected papers 
ISSN: 
ISSN 20297092 online 
ISBN: 
9786094576409 / 9786094576904 CD 
Year: 
2014 
Publisher: 
Vilnius Gediminas Technical University Press Technika 
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Abstract
The present paper deals with the bus network design problem. Such problem is formulated as an optimization problem involving the
minimization of all resources and costs related to the public transport system. The optimization problem is subject to user equilibrium on
public transport network as well as to the bus capacity constraints and a set of feasibility constraints on route length and line frequency.
The objective function is defined as the sum of operator’s costs and users’ costs. The input data are the public transport demand matrix,
the characteristics of road network, the operating and users unit costs. Outputs are routes and frequencies for the lines of the public
transport network. The performances of the network are estimated by a hyperpath transit assignment model, which reproduces the choice
behaviour of transit users. The solving procedure consists of a set of heuristics, which includes a first routine for the definition of the
roads and the zones to be served, a second step for the routes generation and then a genetic algorithm for finding a suboptimal set of
routes and associated frequencies. The GA is implemented in the C# language as a parallel genetic algorithm while the fitness evaluation
requires computing, for each solution generated, the two terms of the objective function by simulating the public transport network with
the EMME software. The proposed procedure will be implemented on a real large size network (two districts in the city of Rome), in
order to compare its effectiveness with the performances of the existing transit network and to provide an extensive sensitivity analysis in
bus frequency changes.
Keywords:Public transport network design; frequency setting; metaheuristics.
