The Sumner Tunnel is a vehicular tunnel located in Boston, Massachusetts. It connects the neighborhoods of East Boston and Downtown Boston, allowing for easier travel across the Boston Harbor. Opened in 1934, the tunnel is named after Charles Sumner, a prominent U.S. Senator from Massachusetts. The tunnel is approximately 1.6 miles long and features two lanes for traffic. It is an essential part of the city's transportation infrastructure, helping to reduce congestion on surface streets. The Sumner Tunnel is operated by the Massachusetts Turnpike Authority and is a key route for commuters and visitors alike.