Transportation Asset Management Case Studies
HERS-ST: The New Mexico Experience
Where Is New Mexico Today?
New Mexico has used HERS-ST to develop the need projections for its long-range plan since the program's inception, with HERS-ST fully integrated into NMDOT's long-range-plan process by 2003.
New Mexico is exploring the use of HERS-ST as an asset management tool and is using it to prioritize corridor needs in the long range planning process.
That wasn't always the case. Prior to 2005, the DOT's planning division used a full engineering needs analysis for estimating future highway needs.
In 2005, however, when the Governor's Infrastructure Conference asked for a summary of New Mexico's highway needs, the planning division suggested a new approach - using the constrained number from a HERS-ST analysis instead of the traditional method. The bottom line? NMDOT had to have a credible number.
The HERS-ST number that New Mexico provided showed $11 billion in 20-year needs, a lower number than what had been provided in years past. When questions arose about that "lower" number, NMDOT planners explained that this figure represented projects with a benefit-cost ratio of 1 or more. It wasn't what the DOT had provided in years past - a list of every project that anyone could think of.
And NMDOT already sees the usefulness of HERS-ST expanding as State DOTs strive to meet requirements in the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEALU), namely estimating the maintenance costs of planned improvements and establishing the operational functionality of a system. "We can address these issues in our long-range plan utilizing HERS-ST," says Senior Planner Roy Cornelius.
Seven Ways NMDOT Uses HERS-ST
- Determining long-range planning needs.
- Calculating benefit-cost ratios for all "GRIP" projects.
- Generating system condition summaries.
- Estimating maintenance costs.
- Estimating operational costs.
- Calculating impacts on highway users at different funding levels.
- Providing a "user interface" to access and view (via GIS, tables and graphs/charts) highway data in one location.