[sustran] System dynamics in transport policy analysis

[Harun al-Rasyid Sorah Lubis]

Most  applied model in transport are non-structural and lack of feedback
mechanisms.
Therefore , we have to select some scenarios in order to predict the
uncertainty of the future behavioural response.  And partly problem of GIGO
is one of the nightmare. A simple illustration of private vs. public
transport strategy, i.e. building more roads (capacity) is predicted  by the
model to ease congestion, in fact what happen in the future is even more
congested. This is explained, why this family of model is lack of feedback
mechanism. Although, perhaps, other choice dimensions apart from route were
considered, but how the construction and motorisation lobbies would took
place during the time horison were out of hand.

Feedback-rich model is belong to , some says, the system dynamics, which
capable of telling the whole structure of the problem and their
interactions. Maybe people recently  involving in the policy analysis of
transport and the environment  could share their view on this issue.  The
reasons I asked this is due to the danger of using the non-structural model
in a developing world problem, as delay of policy implementation may take
place, high growth, etc. , apart from the basic problems of the lack of data
base and lack of funding.



Harun al-Rasyid S. Lubis             http://trans.si.itb.ac.id
Traffic Lab, Transport Engineering Division
Dept. of Civil Engineering - ITB
Jl. Ganeca 10 Bandung 40132 - Indonesia
Tel/Facs. +62 22  250 23 50  halubis at trans.si.itb.ac.id