Bobby Hopper Tunnel
|Entering the tunnel northbound|
|Other name(s)||Bunyard Tunnel (prior to designation)|
|Location||unnamed mountain near Winslow, Arkansas, in south Washington County|
|Operator||Arkansas State Highway and Transportation Department|
|Design engineer||J. F. Shea Company|
|Length||1,595.2 ft (486.2 m)|
|Number of lanes||4|
|Tunnel clearance||25 ft (7.6 m)|
|Width||38 ft (12 m)|
The tunnel's twin bores are each approximately 1,600 feet (0.49 km) in length, 38 feet (12 m) wide and 25 feet (7.6 m) tall (as measured from the roadway to the top of the tunnel arch). A prominent feature of the tunnel is the noticeably inclined gradient of each bore and its associated roadway. Southbound traffic experiences a significant descending gradient inside the tunnel, while northbound traffic experiences a corresponding ascending gradient.
The tunnel was named for the director of the Arkansas Highway Commission (a resident of nearby Springdale, Arkansas) during the time of its construction. This is the only highway tunnel in the State of Arkansas. Arkansas has seven railroad tunnels but only one highway tunnel. Named for the Arkansas Highway Commission director at the time of the tunnel’s construction, Bobby Hopper, the northwest Arkansas commission representative from Springdale (Washington County), the Bobby Hopper Tunnel is located on Interstate 49 in Washington County just north of the Crawford County line with its closest exit at Winslow.
U.S. Highway 71, once classified as “one of the most dangerous highways in America,” includes a perilous stretch between Alma and Fayetteville through the Ozark Plateau. Thus, construction of an alternate route was designed to make the trip safer, as well as reduce travel time. Approved in 1987 and completed in 1999, at a cost of $458 million, the alternate route, eventually named Interstate 49, had an obstacle of an unnamed 1,800-foot (550 m) peak just north of the Washington–Crawford County line in what John Haman of Arkansas Business called “smack in the middle of motoring wilderness.” A tunnel feasibility study was awarded to Garver USA which subcontracted with Sverdrup Corporation of Maryland Heights, Missouri, and TapanAm Associates, Inc., of Kansas City, Missouri, to determine the best option—a tunnel. The alternative would disfigure the topography and necessitate a 200-foot (61 m) cut creating 8 million cubic yards of debris to be disposed of, as it was not usable within the project.
At an elevation of 1,640 feet (500 m) above sea level, twin parallel tunnels were mined, not bored, through the mountain in a horseshoe contour since a circular shape, like that used in sewer or train projects, was not needed. Blasting, drilling, and excavation removed native shale and sandstone rocks, slowly chipping to the desired width and length. The hollowed-out channel was lined with reinforced concrete, as were both openings. The finished total length is 1,595.2 feet (486.2 m), with a width of thirty-eight feet and a height of twenty-five feet, as measured from the roadway to the top of the arch, allowing for two lanes of traffic and shoulder space on each portal. The tunnel has an inclined pitch in that southbound traffic ascends inside the tunnel while northbound traffic descends, with both at the same grade. Cross-passages occur every 265 feet (81 m) allowing for five emergency ways in. Besides paved openings, the tunnel has traffic signals, lighting, message signs, carbon monoxide monitors, fire protection, and closed-circuit television systems to monitor traffic remotely at the Fort Smith highway department district headquarters.
- Arkansas State Highway and Transportation Department (PDF). 2009 ADT Map, Washington County, Arkansas (Map). http://www.arkansashighways.com/planning_research/technical_services/TrafficCountyMaps/2009ADT/counties/WASHINGTON.pdf. Retrieved 2011-05-17.