Cost-Effectiveness of Capping Freeways for Use as Parks: The New York Cross-Bronx Expressway Case Study.

OBJECTIVES: To examine health benefits and cost-effectiveness of implementing a freeway deck park to increase urban green space.

METHODS: Using the Cross-Bronx Expressway in New York City as a case study, we explored the cost-effectiveness of implementing deck parks. We built a microsimulation model that included increased exercise, fewer accidents, and less pollution as well as the cost of implementation and maintenance of the park. We estimated both the quality-adjusted life years gained and the societal costs for 2017.

RESULTS: Implementation of a deck park over sunken parts of Cross-Bronx Expressway appeared to save both lives and money. Savings were realized for 84% of Monte Carlo simulations.

CONCLUSIONS: In a rapidly urbanizing world, reclaiming green space through deck parks can bring health benefits alongside economic savings over the long term. Public Health Implications. Policymakers are seeking ways to create cross-sectorial synergies that might improve both quality of urban life and health. However, such projects are very expensive, and there is little information on their return of investment. Our analysis showed that deck parks produce exceptional value when implemented over below-grade sections of road.