On the Job: Mindful Planning Paves Way for New California Highway

Quantm software finds optimal route for toll road while adhering to environmental regulations

Quantm software integrates transportation planning with environmental considerations, as exemplified by the Southern California Foothill Transportation Corridor-South project, undertaken in concert with the TCA (Transportation Corridor Agencies) and the appointed consultant, the Corridor Design Management Group. The mega-project comprises the planning, design, building and operation of a toll road from Oso Parkway in Rancho Santa Margarita to the I-5 Connector at the Orange/San Diego County border in Southern California.

Complicated Undertaking
With the need to demonstrate compliance with the National Environmental Policy Act (NEPA) and Section (4f) of the Department of Transportation Act -- a key requirement of every transportation infrastructure undertaking in the United States -- the process of route selection for transportation projects has achieved a level of complexity that can and often does stop transportation infrastructure projects in their tracks.

The Quantm system for route alignment selection helps transportation planners integrate environmental, community, cultural, engineering and cost factors into a single analysis. By integrating the large amounts of data required by agencies involved in the environmental protection process in the United States, the system helps achieve the objective of reducing project impacts on the environment, including demonstrating that all reasonable alternatives have been considered, as required by NEPA and the California Environmental Quality Act. The system has been successfully applied on road and rail projects worldwide.

Figure 1. The technology allows the project team to demonstrate that a comprehensive study has been undertaken.

Positive Net Results
Quantm's route-optimization technology dramatically improves the process of integrating the information that comes from the various agencies involved in the NEPA process, resulting in reduced environmental impacts, improved relations with stakeholders and the local community and a substantially curtailed planning cycle, the company reports.

Figure 2. Alignment comparisons of alternative toll road routes in the Quantm system.

Figure 3. One alternative route is displayed over an aerial photography background.

The success of the Foothill Transportation Corridor-South project, located in a part of Southern California dense in population and natural habitat, demonstrates how the software enabled the project team to balance environmental and economic concerns to satisfy all stakeholders. The collaborative approach it fostered enabled environmental streamlining that delivered, among other things:

• Reduced impact to riparian ecosystems (wetlands) from 107 acres to 49 acres
• Reduced impact to sensitive species by completely avoiding the Pacific Pocket Mouse habitat.
• Reduced landslide risk/disturbance limits by avoiding many of the existing landslides by identifying roadway geometry that more closely follows the natural terrain.
• Reduced residential displacement from 32 homes to zero.

The technology also helped reduce earthworks and structures, delivering construction cost savings of more than $80 million, Quantm reports.

Great Improvement
James Brown, TCA chief engineer, explains, "Prior to using Quantm, we spent two years developing alternative route scenarios using conventional GIS and CAD systems, but found them unable to satisfy the multiple interests of different project stakeholders. Quantm was able to greatly improve the collaboration between the engineering and environmental project teams."

Figure 4. The system provides 3D analysis throughout.

"The power of the Quantm system means that alternative scenarios can be investigated in just days," says Alan Griffiths, Quantm chairman. "This allows the planners to demonstrate comprehensive consideration of each stakeholder's priorities, achieve consensus and maintain the momentum of the project."

For the Foothill Corridor project, the agencies defined for consideration more than 150 different elements -- including wetlands, sensitive habitats, cemeteries and utilities -- resulting in 3,750 individual constraint zones input into the system utilizing existing GIS and other data sources.

The technology also provided an audit trail that documents how the recommended alignments were derived, recording the sequence of iterations and the project decisions made by the planners, engineers and other decision makers - all of which is helpful when justifying the selection of one alternative or when negotiating mitigation cost agreements with resource agencies.

Figure 5. Scenario log information, or audit trail, provided by the Quantm software.