Interval-Based Approach to Managing ITS Assets / Nevada DOT
Nevada DOT recognized that the level of investment in ITS equipment (e.g., closed-circuit cameras, dynamic message signs, flow detectors, highway advisory radios, environmental sensor stations, and ramp meters) was increasing significantly and the importance of this equipment to network operations was growing. As a result, the DOT chose to establish a method of managing its ITS assets that would minimize the risk of failure and provide information to support budgeting activities. However, since the DOT had limited data on its ITS components, a process was developed that relied on the following factors to establish maintenance cycles:
- Historical performance
- The typical timeframe before the software became outdated
- Manufacturer recommended service life
- To determine the condition of ITS traffic cameras, Nevada DOT developed a transition probability matrix with four condition criteria based on the device manufacturers’ recommended service life as follows:
- Good – device age is less than 80 percent of the manufacturer’s recommended service life
- Low risk – device age is between 80 to 100 percent of the manufacturer’s recommended service life
- Medium risk – device age is between 100 to 125 percent of the manufacturer’s recommended service life
- High risk – device age is greater than 125 percent of the manufacturer’s recommended service life
The transition probability matrix was used to model ITS asset deterioration and program maintenance actions over a 10-year analysis period via the use of a simple spreadsheet tool. The results of this analysis showed an interval-based approach to managing ITS assets would result in an estimated savings of $1.1 million over a 20-year period.
Source: Nevada DOT TAMP (2018)
Read more in the chapter: 4.3.2 Applying Other Life Cycle Management Approaches