Adding Tunnels as an Ancillary Asset
Asset Management Methodology
The Colorado Department of Transportation is in a multi-phase project to implement strategic and tactical asset management analysis for many different assets maintained by the department. The CDOT Asset Management Investment System (CDOT AIMS implemented in dTIMS by Deighton) currently analyzes the following assets:
- Fleet Equipment
- Geotechnical Hazards
- ITS Devices
- Traffic Signals
For each asset, AIMS completes a life-cycle cost analysis using a number of alternative budget scenarios. First off AIMS analyzes a set of budget scenarios that have very close dollar ranges clustered around historical funding and desired funding.
Following the initial set of clustered budgets, AIMS then analyses a set of budgets that are wide open out using the dTIMS Strategic Analysis Module. This enables CDOT management to quickly assess the impacts of moving large amounts of funding between the different assets.
Finally CDOT completes a Cross Asset Analysis and Optimization using the dTIMS Cross Asset Optimization functionality which investigates where additional funding would be allocated based on an incremental benefit cost optimization where each project for each asset completes for this additional funding. Each asset gets a minimum dedicated amount of funding and then a flexible amount of funding is supplied that each asset can “tap into”. CDOT also establishes a maximum percentage of the flexible funding that can go to any one asset. This prevents one asset from getting all of the flexible funding.
Following the analysis runs, CDOT hosts a budget setting workshop where the results of the AIMS analysis are reviewed for each of the assets and a Delphi process is used to vote on the allocations. The voting results for the budget allocations are then reviewed by the Transportation Asset Management Oversite Committee and presented to the CDOT Transportation Commission for approval. CDOT is a great example where the asset management analysis directly impacts resource allocation.
Incorporating Tunnels into CDOT AIMS
In 2015 – 2016, CDOT completed the implementation of the Tunnel analysis configuration in AIMS. CDOT Maintains a number of simple unmanned tunnels as well as a number of highly complex manned tunnels. The Eisenhower Johnson Memorial Tunnel on I-70 represents over 47% of the entire tunnel network length. Current funding needs for this one tunnel alone exceeds $50 Million Dollars.
In order for Tunnels to gain a seat at the resource allocation table, it was necessary to develop the Asset Management Analysis methodology for inclusion in CDOT AIMS.
The first step in that process was to develop the framework for managing the tunnel assets and then to develop the data collection methodology to support that framework.
Tunnel Components and Tunnel Elements
The tunnel elements are grouped together into components for calculating condition measures.
Element conditions are predicted in AIMS using Markov Transition Probability Matrices developed through the project.
During the AIMS analysis, once the Condition States for the elements and the components are known, AIMS investigates three treatments for every element using criteria developed by the project team:
• Minor Repair
• Major Repair
Tunnel Treatments, Triggers, Resets, and Costs
Analysis Results and Conclusions
During the project, CDOT and Deighton tried two approaches to analyzing the tunnels, the first approach involved treating all components at a tunnel at one time. This approach allows all of the performance metrics to be calculated at once for an entire tunnel and not rolled up from the element level following the analysis. Unfortunately this approach was not practical due to the very high funding requirements EJMT ($50 Million).