Last Chance Grade is a 3.5-mile segment of Highway 101 that serves as arterial gateway to California’s North Coast. Residents and businesses lack options for access to this rural, isolated region. It is prone to landslides and closure, leading to concern about costs to motorists and regional tourism if a long-term closure occurs. California DOT used TREDIS, along with local business interviews and market analysis, to assess the economic impacts and benefit of investing in rebuilding and realigning the road to make it resilient to rockslides, saving costs of continual pavement repairs and eliminating risk of closure.

The TREDIS economic impact analysis considered effects of a worst case scenario where the road is closed, requiring a 320-mile (6-hr) detour required for the route between Brookings and Arcata. The analysis covered benefits of avoiding higher costs of repairs, detour-related time and cost, loss of tourism and loss of food product shipments.