Health benefits of parks are more strongly associated with driving access than walking access in the contiguous United States

• We created maps of walking and driving access to parks for the contiguous U.S. • 151 million people lack walking access, mostly in low-income and rural areas. • Park access is associated with health benefits; driving access has a stronger link. • New parks near cities can save billions of dollars annually in health care costs. Parks provide significant benefits to well-being, however previous assessments of park access have often ignored suburban and rural areas and used coarse measures of proximity alone. We address these limitations with a novel conceptual model that is adaptable to any location globally, framing park access as the area of parks reachable within residents’ uniquely constrained travel range for a given transportation mode. We demonstrate the model’s application by estimating both walking and driving access to public parks in the contiguous U.S., considering social barriers and trail and road network analysis. Both walking and driving access to parks are associated with better community health and happiness, including lower modeled rates of obesity, high blood pressure, and diabetes in adults. However, driving access has a stronger association, suggesting that park benefits extend beyond their immediate surroundings. Our dataset also reveals that 151 million people, or 46 % of the population, live in “park deserts,” lacking walking access to a park, with lower-income and rural individuals having the least access. While urban parks remain essential, investing in larger parks outside cities but within driving distance may yield greater public health benefits. These strategically located new parks (increasing public land by 0.2 %) might save $2.2 billion annually in health costs, outweighing park management costs and recouping initial investment costs within two years.