The Pennsylvania Turnpike Commission is warning motorists of a continuous, 55-hour weekend closure planned between the Lehigh Valley Interchange, Exit 56, and the Mahoning Valley Interchange, Exit 74, on the PA Turnpike’s Northeastern Extension (I-476) from Friday to Monday for bridge work.

The roadway will be closed in both directions starting at 9 p.m. Friday until 4 a.m. Monday.

The lengthy closure is needed for crews to safely demolish the current bridge that carries the Turnpike over State Route 309 in South Whitehall Township, Lehigh County at milepost A58.88 while replacing it with a new steel superstructure that will be installed.

The construction technique being used, Accelerated Bridge Construction, eliminates the need for months or years of single-lane traffic patterns and other motorist restrictions by closing that part of the roadway for a limited period over a weekend.

The new superstructure, which has been under construction since 2018, is being built near the existing bridge. The 90-foot long bridge opened to traffic on April 1, 1957, and today carries roughly 30,000 vehicles per day, combined north/south.

For 55 hours, the PA Turnpike will implement a detour of I-476 in both directions.

Route 309, located beneath the bridge, will also be closed between Chapmans Road and Snowdrift Road. Detour routes will be marked for through and local traffic.

Motorists are urged to avoid the area if possible, but if traveling in this region, drivers should pay close attention to the orange and black directional signs. “Accelerated Bridge Construction is a technique that drastically decreases the traffic impact to the traveling public while reducing worker exposure in construction zones,” said Wally Wimer, PA Turnpike Senior Bridge Engineer.

“It also eliminates the need for months or years of shoulder closures, single-lane traffic patterns and other restrictions for motorists. We compress the traffic control into one weekend.”

While there are many benefits to the ABC technique, Wimer cautions motorists that the bridge replacements could create significant, regional travel delays and encourages motorists to consider alternative routes, travel during off-peak hours or avoid the area altogether during the weekend closures as the detours add substantial travel time.

“Motorists traveling during these weekends could face lengthy detours in some areas that will add to their travel times,” said Wimer. “As a result, we strongly urge customers to steer clear of these areas during the detour weekends or build in plenty of extra travel time.”

The authorized detour routes will be clearly marked for both through traffic and local traffic. Motorists should pay close attention while driving the detour, looking for the orange-and-black directional signs.

The PA Turnpike’s September closures are scheduled as follows:

The first closure will take place from 9 p.m. Friday, Sept. 6 through 4 a.m. Monday, Sept. 9, on the Northeastern Extension (Interstate 476, milepost 58.88) in Lehigh County, just north of the Lehigh Valley Interchange (Exit 56). The detour exits are the Lehigh Valley Interchange (Exit 56) for northbound traffic and the Pocono Interchange (#95) for southbound traffic. The authorized detour route directs motorists to Route 22, Route 33 and Interstate 80.

(NOTE: Local travelers heading southbound on the PA Turnpike will be able to drive past Exit 95/Pocono and continue to exit at Exit 87/Route 903 E-ZPass Only or Exit 74/Mahoning Valley. The Turnpike will be closed southbound at Mahoning Valley.)

The through-traffic detour is approximately 70 miles.

For the last several months, crews have been constructing the new bridge segments near the existing bridges. When the highway section is closed, workers will demolish the existing bridges and replace them with the new spans.

The PA Turnpike has more than 800 bridges on its system which are regularly inspected to ensure their safety and integrity. These two bridges were slated to be replaced due to their age.

For more details and maps of the detours visit www.paturnpike.com/ABC.