The Ohio Department of Transportation (ODOT) has opened Phase One of the Northeast Expressway Transformation (NExT), which includes the redesigned SR 161 westbound ramp to I-270 south on the northeast side of Columbus.
The ramp includes a first-of-its-kind 440-ft. (134 m) tunnel. Along with the new ramp and tunnel, the westbound lanes of the Single Point Urban Interchange (SPUI) were opened, connecting Sunbury Road and SR 161.
Work on the NExT project began in June 2004. The $134 million project includes 18 ramps, 17 bridges, 65 retaining walls, and 5 mi. (8 km) of roadway, covering 300 acres (121 ha) of land.
The tunnel “was designed by open cut — no boring —just digging,” said Nancy Burton, public information officer, ODOT District 6. “There were already three flyover ramps planned which would have made another flyover much too high.”
The tunnel is 30 ft. (9 m) deep, has 564 lights, a fire detection system, two fire hydrants, and six alarm boxes.
“It took three years to build the tunnel,” said Burton. It was designed by Evin, MacWhart, Hambleton, and Tilton of New Albany, Ohio.
According to ODOT, rebuilding three of the four ramps at the SR 161/I-270 interchange was critical to handling the increased traffic in the area. Studies showed the area to be one of the most congested areas in the Columbus metropolitan area.
“The fire detection system is designed to trigger an alarm when the inside temperature reaches 190 degrees,” said Burton. “A coded wire system signals the control panel on the outside of the tunnel, along with the fire hydrants.”
“The 564 lights on the interior of the tunnel are brighter during the day so there is less eye adjustment when entering and leaving the tunnel,” said Burton. The lights are dimmer at night.
ODOT is opening the westbound lanes and ramps first. East bound traffic will open in a few weeks.
The project, which will be completed in three years was originally planned to take 3.5 years at a cost of approximately $126 million.
The new interchanges at I-270 and SR 161 were designed to eliminate weaving, merging and pinch points by replacing old cloverleaf ramps with new flyover ramps. The new ramps allow motorists to connect directly with the freeway rather than sharing a lane with those entering or exiting.
The project has added one to two lanes on I-270 from just north of SR 161 to about Sunbury Road, and on SR 161 from I-270 to Little Turtle Way.
A SPUI replaced the old interchange at Sunbury Road and SR 161. A SPUI “can pump more traffic through the intersection while taking the least amount of right of way,” according to ODOT.
The original I-270/SR 161 interchange was designed to handle approximately 58,000 vehicles per day. It currently handles about 135,000 vehicles per day. That number is expected to rise to 193,000 by 2020, according to ODOT.
Outdated and overburdened, Sunbury Road has sustained the most extensive traffic congestion during the rebuilding. Originally, the Sunbury Road/SR 161 interchange was built to handle about 21,000 vehicles per day. Current counts are close to 90,000 per day and expected to reach 188,000 by 2025.
Because of the population density in this mostly residential area, several projects were being worked on simultaneously. The Dempsey Road Bridge over I-270 was closed for lengthening. I-270 was widened to accommodate the new ramps. Noise walls also were being erected, and became a part of the project rather than being built a year or two later under a separate contract. The relocation and widening of SR 161, located between New Albany and Granville, included 12.6 mi. (20 km) of Sunbury Road.
Much of the traffic problems in the area were caused by motorists who were entering the highway, being forced to share lanes or weave across lanes where other motorists were exiting the highway. In the 1960’s when traffic volumes were much lower, this worked. But with 130,000 vehicles per day using the SR 161/I-270 interchange, this is no longer safe or efficient.
“To eliminate this problem, we had to separate all of the SR 161 traffic from the I-270 traffic,” according to an ODOT District 5 press release.
This is the last of a series of projects that began in 1993 to accommodate traffic growth and development on the northeast side. These two projects were originally scheduled to begin in 2005, but were moved to 2004 to complete work sooner. Completion is expected in June 2008.
Traffic pattern shifts have become the norm as work has progressed. ODOT has set up an official website for motorists to keep up with the changes. Visitors to www.161next.org also may take a virtual drive through the new tunnel.
“It takes five seconds at 55 miles per hour to drive through the new tunnel,” said Burton. CEG