Transportation Asset Management Case Studies
HERS-ST: The Indiana Experience
3. How did Indiana Get There?
Figure 5: The I-70 ramp west of Indianapolis, a Fast Track project. Photo courtesy of INDOT |
After months of work with the systems consultant, Indiana finalized the HERS-IN software in 1998. The customized version was congestion-based and included a process to convert the State's road inventory database to HPMS for HERS-IN. The result? Indiana finally had a 100 percent database for the 12,000 miles of the State jurisdictional system and didn't have to rely on sample data when evaluating the State's long-range needs.
The customized software contained several other special features, including an override element that allowed software-generated improvements to be replaced with analyst-specified improvements; the ability to produce maps; and the capability to evaluate capacity expansion projects and estimate the impact of each capacity improvement on traffic system-wide.
With HERS-IN in place, INDOT began looking at the larger picture - developing systems analysis programs that would generate a project-specific long-range plan. The State quickly discovered that it needed a suite of tools to make that goal a reality. Those tools include the following:
- Indiana Statewide Travel Demand Model (ISTDM). INDOT's ISTDM is the cornerstone for the State's various systems planning tools, including HERS-IN. The model is used to provide the analytical framework for assessing transportation system performance and deficiency analysis, long-range plan development and systems-level project analysis, as well as the spatial analytical framework for many of the DOT's management systems.
- Traffic Forecasting Tool (TFT). First developed in 1998, the TFT provides link-based travel forecasts for Indiana's State jurisdictional system. Link-based information is then displayed on a graph showing forecasted volume, available capacity and level of service (LOS).
- Major Corridor Investment Benefit Analysis System (MCIBAS). Initiated in 1995, MCIBAS offers benefit-cost analysis of system alternatives in INDOT's ISTDM, including evaluation of corridor-level economic development benefits. The MCIBAS process uses the ISTDM to measure the direct impact of a major highway improvement on existing and future traffic volumes, speeds and distances. MCIBAS also includes a post processor that converts the travel demand impacts into dollar values for travel time, travel cost and safety benefits.
"You can do a full needs analysis in HERS-ST," Smith states, "but you still need to use all your tools."