Project assessment for transport routes
A cost-benefit analysis and an impact assessment are used to assess transport infrastructure projects. A project assessment ensures that the best project option advances in planning. Ultimately, the information produced by the project assessment supports the decision to implement the project. The assessment of road, rail and waterway projects is described in transport mode specific instructions. The instructions for all modes of transport are based on the general guidelines for transport infrastructure project assessments, which contain the main principles for the assessment common to all modes of transport. The unit values used in the cost-benefit calculations are presented in their own publications.
Impacts measured in money are calculated using a cost-benefit analysis
The cost-benefit analysis assesses the change in the net benefits resulting from the construction costs of the project and the implementation of the projects. The calculation takes into account, for example, impacts on
- travel time,
- emissions and
- the operating costs of the vehicle, vessel and train.
In the assessment, the estimated impact amounts are multiplied by the unit values for the different cost categories derived from prices obtained from or valued on the market.
The profitability calculation assesses the difference between the project and its comparison option. If the savings are higher than the investment, the cost-benefit ratio is more than one and the project is profitable in terms of monetary impacts. Even if the cost-benefit ratio is less than one, this does not necessarily mean that the project will not be profitable as the cost-benefit ratio does not take into account all the project’s impacts. Similarly, when the cost-benefit ratio is more than one, the project may not be profitable, as it may have significant disadvantages that are not included in the calculation.
Weighing objectives and impacts
An impact assessment describes the extent to which the project options or the project produce different impacts. Impacts can be assessed more extensively in an impact assessment than in a cost-benefit analysis, as all impacts relevant to decision-making may be assessed.
In the scope of the assessment, project impacts are compared with the so-called impact potential, which describes how much impact the project could have in the best and worst case scenarios. The impact assessment also describes whether the impact is in the desired direction or contrary to the objective.