In order to perform a cost/benefit analysis, it is necessary to determine both which costs and which benefits should be included in the analysis. This is not a straightforward decision, as costs and benefits are generally intertwined: the broader the costs, the broader the benefits.
Based on the range of possible cost and benefit approaches and ongoing discussions with practitioners, the Connected Corridors team recommends a strategy that is I-210 Pilot-specific:
- Considering expenditures exclusively on the I-210 corridor, only for items that would never have been undertaken without the need for a centralized decision support system
- Considering costs and benefits only during incidents
This recommendation is conservative in both the costs and benefits to include.
Ongoing/Continuing – 10-year time period:
It should be noted that:
- This does not include any community benefits. While these exist, it is unclear how to value them.
- This does not include any costs for ITS element upgrades. While a certain percentage of the overall ITS upgrade costs required by the Connected Corridors decision support system could be included, it is difficult to understand exactly what percentage to use.
- Some practitioners believe that all ITS element upgrade costs justified as part of this program should be included. However, cost justification does not equate with actual cost allocation to the project for a cost/benefit analysis.
- This strategy also does not count costs for upgrades to software systems that will be used across multiple corridors. A percentage could be applied here, but that percentage is open to discussion.
- Overall, it appears that standard transportation-related cost/benefit analysis is not ideally suited for ITS projects. In standard construction, changes to roadway infrastructure are only usable in one location and are available all the time.
In addition, the following considerations should be part of the discussion of costs and benefits:
- Costs and benefits evaluations should be based on a before/after comparison of corridor operations.
- Data characterizing costs and benefits after the launch of the Pilot ICM system should ideally be measured after the system has been in operation for one year.
- Simulation and estimation may be used early in the evaluation process. However, without an accurate tally of costs and with the possible variance in measured benefits from simulated benefits, the possibility for significant errors exists.