The Detroit Free Press/Talmer Bank Marathon is a 42.195 km race run every October in Detroit, Michigan, United States and Windsor, Ontario, Canada since 1978.
 The predecessor to this race was the Motor City Marathon which started in 1963 and featured multiple laps on Belle Isle.
 The marathon course is international and has featured the Detroit-Windsor Tunnel for all but two years of its existence.
 From 1978 to 1998 the race started in Windsor and finished in Detroit.
 The current course crosses the Ambassador Bridge and the Detroit-Windsor Tunnel between Detroit and Windsor.
 Due to its use of the tunnel, the race is able to boast that it has the only official underwater international mile in the world, as the tunnel runs underneath the Detroit River.
 The race is a USATF-certified, Boston-qualifier course.
Maryland Route 17 (MD 17) is a state highway in the U.S. state of Maryland.
 The state highway begins at the Virginia state line at the Potomac River in Brunswick, where the highway continues south as Virginia State Route 287 (SR 287).
 MD 17 runs 29.49 mi north from the Brunswick Bridge to the Frederick–Washington county line near Wolfsville.
 The state highway serves as the main north–south highway of the Middletown Valley of western Frederick County.
 MD 17 connects Brunswick and Wolfsville with Rosemont, Burkittsville, Middletown, and Myersville.
 The state highway also connects those communities with the valley's main east–west highways, which include U.S. Route 340, US 40 Alternate, Interstate 70 (I-70), and US 40.
Marina Boulevard is a road in Singapore running along the western side of Marina Bay.
 Starting at Raffles Place intersecting with Collyer Quay and running south, there are a number of landmark buildings along the length of it.
 One Marina Boulevard and One Raffles Quay form bookends of its northern terminus.
 Located along it are The Sail @ Marina Bay, the landmark promontory space, Central Linear Park (under construction), Marina Bay Financial Centre, and eventually Marina South Pier and the future Marina South residential community.
 The Common Services Tunnel runs underneath it.
 The first part of the road from Coller Quay to Marina View Link is a two-way street and the part from Marina View Link to the East Coast Parkway (ECP) is a five-lane, one-way road towards the ECP.
Otterøya or Otrøyna is an unpopulated island in Bømlo municipality in Hordaland county, Norway.
 The 0.45 km2 island lies in the Bømlafjorden, southeast of the islands of Føyno, Nautøya, and Spyssøya.
 The southern part of the island is a nature reserve.
 The Bømlafjord Tunnel runs underneath the island.
Interstate 78 (I-78) is an east–west route stretching from Union Township, Lebanon County, Pennsylvania to New York City.
 In New Jersey, I-78 is called the Phillipsburg–Newark Expressway and the Newark Bay Extension of the New Jersey Turnpike.
 The highway runs for 67.83 mi in the northern part of the state of New Jersey from the Interstate 78 Toll Bridge over the Delaware River at the Pennsylvania state line in Phillipsburg, Warren County east to the Holland Tunnel under the Hudson River at the New York state line in Jersey City, Hudson County.
 The Phillipsburg-Newark Expressway portion of I-78, formally called the Lightning Division Memorial Highway, runs from the Phillipsburg area east across rural areas of western New Jersey before entering suburban areas in Somerset County.
 The road crosses the Watchung Mountains, widening into a local-express lane configuration at Route 24 as it continues through urban areas to Newark.
 Here, I-78 intersects the mainline of the New Jersey Turnpike (I-95) and becomes the Newark Bay Extension, crossing the Newark Bay Bridge and continuing to Jersey City.
 The route, along with Route 139, follows a one-way pair of surface streets to the Holland Tunnel.
Route 17 is a state highway in Bergen County, New Jersey, United States, that provides a major route from the George Washington Bridge, Lincoln Tunnel and other northeast New Jersey points to the New York State Thruway at Suffern, New York.
 It runs 27.20 mi from Route 7/County Route 507 in North Arlington north to the New York border along Interstate 287 in Mahwah, where New York State Route 17 continues into New York.
 Between Route 7 and Route 3 in Rutherford, Route 17 serves as a local road.
 From Route 3 north to the junction with U.S. Route 46 in Hasbrouck Heights, the road is a suburban arterial with jughandles.
 The portion of Route 17, from US 46 to Interstate 287 near the state line in Mahwah, is a limited-access road with all cross traffic handled by interchanges, and many driveways and side streets accessed from right-in/right-out ramps from the right lane.
 For three miles (5 km) north of Route 4, well over a hundred retail stores and several large shopping malls line the route in the borough of Paramus.
 The remainder of this portion of Route 17 features lighter suburban development.
 The northernmost portion of Route 17 in Mahwah runs concurrent with Interstate 287 to the New York border.
The Lincoln Tunnel is an approximately 1.5 mi set of three tunnels under the Hudson River, connecting Weehawken, New Jersey and Midtown Manhattan in New York City.
 An integral conduit within the New York Metropolitan Area, it was designed by Norwegian-born civil engineer Ole Singstad and named after U.S. President Abraham Lincoln.
 It is one of two automobile tunnels built under the river, the other being the Holland Tunnel.
 In 2016, the Lincoln Tunnel carried a daily average of approximately 52,632 motor vehicles (or 19,210,919 for the year).
Gray Summit is an unincorporated community and census-designated place (CDP) in Franklin County, Missouri, United States.
 The population was 2,701 at the 2010 census.
 Also called "Gray's Summit", it was founded by Daniel Gray of New York who built a hotel here in 1845.
 This community was the highest point on the Missouri Pacific Railroad between St. Louis and Jefferson City, Missouri; a railroad tunnel runs underneath the community.
 It is located on Interstate 44 and is home to Purina Farms and the Shaw Nature Reserve.
The Saigon River Tunnel is an underwater tunnel that opened on November 20, 2011.
 It runs underneath the Saigon River in Ho Chi Minh City, the largest city of Vietnam.
 The tunnel was built with capital from JICA's ODA, in conjunction with a consortium of Japanese contractors.
 The tunnel connects the existing urban center of Ho Chi Minh City with Thu Thiem New Urban Area in District 2.
 The Saigon River Tunnel is part of the , an important road project under construction to ease the congestion of transport in the inner city as well as transportation from downtown to the Mekong Delta region.
 The existing downtown was previously only linked with the Thu Thiem New Urban Area by many bridges, namely: Thủ Thiêm Bridge, Phú Mỹ Bridge and Ba Son Bridge.
The Prudential Tunnel is a tunnel along the Massachusetts Turnpike and Interstate 90 in Boston that runs underneath the Prudential Tower complex.
 It was created in 1965 as part of the first extension of the Turnpike into Boston.
 The tunnel has been criticized for its poor lighting in comparison to the newer Tip O'Neill Tunnel, Fort Point Tunnel, and Ted Williams Tunnel.
 In 2014, a hole was punched in the wall of the tunnel following an accident involving a large truck.
 The tunnel has since been repaired and is fully operational again.
 One exit is contained within the tunnel, the Copley Interchange on the Mass Turnpike.

Question: Which tunnel on Route 17 runs underneath the Hudson River?
Answer: Lincoln Tunnel