Papago Freeway Tunnel

Papago Freeway Tunnel
Carries	10 lanes of I-10 (5 westbound, 5 eastbound) plus 1 unused gated tunnel for city buses / emergency vehicles
Crosses	Margaret T. Hance Park
Locale	Phoenix, Arizona
Maintained by	Arizona Department of Transportation
Total length	2887 feet
Opened	August 10, 1990
Coordinates	33°27′43″N 112°04′21″W / 33.462058°N 112.07252°W / 33.462058; -112.07252Coordinates: 33°27′43″N 112°04′21″W / 33.462058°N 112.07252°W / 33.462058; -112.07252

The Papago Freeway Tunnel, better known to Phoenix residents as the Deck Park Tunnel, is a vehicular tunnel built underneath Downtown Phoenix. It was built as part of Interstate Highway 10 in Phoenix, Arizona.

Route

The tunnel extends from approximately North 3rd Avenue to North 3rd Street. At 2,887 feet (879.95m), it ranks as the 42nd longest vehicular tunnel in the US. The tunnel was the last section of Interstate 10 to be completed nationwide. There is a plaque dedicated to the commemoration of the tunnel in Margaret T. Hance Park.

Margaret T. Hance Park

Above the tunnel exists a park that was named after former Phoenix Mayor Margaret Taylor Hance a few months after her passing in 1990. During her mayorship, Hance was a strong proponent of the tunnel and the park.

Design

The tunnel, which is more of a "table" design rather than an actual tunnel, is divided into two tubes, each carrying five lanes of one-way traffic flanked by two emergency lanes. Each of the two tubes can carry up to 16,000 vehicles per hour. Between the two tubes exists a single-lane tube that was designed as an express terminal for city buses. The tube is unused, and the approaches on both sides of the tunnel are gated off.

Ventilation and Equipment

The Deck Park Tunnel was designed to be ventilated naturally, using the car's energy to help propel air through the tubes. In times of heavy traffic or in the event of a fire in the tube, each tube has four backup fans that provide ventilation, in order to prevent the dangerous buildup of carbon monoxide.

The tunnel has a large diesel generator approximately 50 meters east of the westbound entrance to the tunnel, ensuring that the lighting, video surveillance, and intercoms have continuous power even during an outage. For the safety of motorists, intercoms are located every 150 feet (46 m) within the tunnel.