Improving Transport Project Appraisals
In the Islamic Countries
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Risk assessment
Sensitivity analysis and risk analysis are systematically carried out81. Among the variables
considered by such analyses, inflation is usually included. Overall, sensitivity analysis and risk
analysis appear however to be focused on technical, managerial and financial aspects. By
contrast, a risk analysis on socioeconomic effects (e.g. time saving, noise pollution, etc.) does not
belong to the standard appraisal practices in the country.
Environmental aspects may be considered as a partial exception, thanks to requests advanced
by the Environmental Protection Organisation (especially after COP21 and COP22 Conferences).
CDTIC, for instance, must run the risk analysis model (with probabilities or estimations) on air
pollutants, because the Environmental Protection Organisation would not accept CDTIC’s pre-
feasibility studies (i.e. phase 0) without such calculations.
5.6 Demand analysis
As concerns forecasting techniques, different models are used depending on the organisation in
charge of project appraisal and on the relevant transport mode. An additional differentiation
concerns the level at which the forecasts is performed, i.e. whether at masterplan or project
level.
For road traffic forecasts included in the masterplans, CDTIC uses the Visum model82; such
software is however never used at project level.
In its masterplan, PMO uses simulation models such as iThink83 instead, allowing to identify
which ports (and which areas within the single ports) will be particularly affected by changes in
traffic. For instance, with data on seaborne trade as an input, the organisation can identify which
operations in the ports (e.g. gate operations, or storage operations) will be affected (in which
year and by which degree) by variations in traffic.
At project level, one of the most used software to simulate traffic is Aimsun 84, which is used for
instance by PMO for maritime transport and port infrastructures, and by CDTIC for freeway
projects, such as the Southern Bypass of Teheran, a 158km freeway whose construction started
in 2016 and is predicted to end in 2020.
Further software chosen by PMO are ARENA and SPSS. More in general, however, in the case of
PMO internal modelling of demand, traffic or supply is based on time series (through regression
and extrapolation), on econometric studies done within PMO itself, and on dynamic models as
well.
81 For PPP project, Art. 8 of the PPP Act explicitly requires risk assessment studies as one of the relevant appendices to be
included with the contract.
82 Visum is a software (developed by PTV Group) which allows to perform traffic analyses, forecasts and GIS-based data
management. It models road users and their interactions, and is recognised as a standard tool in the field of transport
planning.
83 This modelling tool (developed by Isee Systems) is used to create interactive simulations.
84 Aimsun is a software modellingmobility networks, which is widely used also in the United States and Europe for purposes
of public transportation planning.