What is the largest city in the United States not connected by a primary interstate?

San Jose, California, is recognized as the largest city in the United States that is not connected by a primary interstate. This is significant because interstate highways typically provide key access points for commerce and transportation; hence, cities with such connectivity often enjoy enhanced economic growth and have more direct routes for travelers.

San Jose's lack of a direct primary interstate connection is due in part to its geographical location and urban planning decisions over the years, which have emphasized other forms of infrastructure rather than the interstate system. The city is served by several highways that provide regional access, but the absence of a primary interstate limits its direct connection to the broader interstate network.

In contrast, the other cities mentioned—San Diego, Las Vegas, and San Francisco—are all connected to primary interstate highways, facilitating greater ease of movement and access. This comparison highlights the unique status of San Jose within the context of its size and infrastructure development.