IF articles

Interaction between project, zonal accessibility and generated demand


This work deals with the development of

a calculation method for “generated or induced demand”

resulting from the construction of a road infrastructure


The materialisation of a percentage of transport demand

generated by the construction of a new infrastructure,

which adds to existing transport demand, is formalised

on the theoretical level. Operationally, the difficulties

of calculation depend on the lack of analytical knowledge

of the “Demand Curve” of the transport system user.

The proposed method is based on the application of

Transportation Analysis extended to the Area of Influence

of the project, understood both as territorial area, with

socio-economic parameters that characterise it, and as a

portion of the Transport Network System, with its technical

and functional variables.

It follows that Transport Demand, both the existing

and the generated one, is represented by the set of movements

taking place in the Area of Influence and therefore,

as a result, by the total vehicular flow on the System or

on the Transport Network.

The User Demand Price for the analytic formulation

of the Demand Curve is related to the overall Demand or


It follows that the implementation of the project determines

the creation of new demand and the latter, being

within the Area of Influence of the project, uses the

portions of Transport Network operational therein and

not necessarily just the new infrastructure that created it.

  • Dicembre
Num. 12
Pag. 983