The kind of chaos is exactly what happened Wednesday morning, and it looks like the situation could last several weeks.

The messy commute unfolded throughout the day after a boom lift being towed on a trailer behind a truck hit the Sitterly Road overpass bridge just south of Exit 9 at about 5:30 a.m., in an incident that state police continue to investigate.

The strike did significant damage to the bridge, and shut down all the Northway’s southbound lanes at a spot where thousands of Clifton Park and Halfmoon commuters heading for Albany usually got onto the interstate each morning. That section of the Northway is used by about 96,000 vehicles per day.

While one southbound lane might open by late Wednesday, the Shenendehowa Central School District notified parents it was advised that the Sitterly Road bridge will be closed for as long as three weeks. The district said parents should anticipate significant delays on bus routes. Use of Exit 9 southbound will be severely restricted during the repairs, and the situation will lead to major delays on Route 9, Route 146, Grooms Road and Moe Road, the notice said.

Traffic backs up down Route 9 southbound in Jonesville Wednesday after a truck towing a trailer with a boom lift struck the Sitterly overpass on Interstate 87 southbound near exit 9 in Clifton Park. (Provided photo — Erica Miller, Daily Gazette)

The DOT confirmed there would be an extended closure, but without providing a timeline other than to say two southbound lanes would be open Thursday morning. “Following a comprehensive inspection and damage assessment by licensed professional engineers of the Sitterly Road overpass on the Adirondack Northway, New York State Department of Transportation crews have begun installing temporary support structures to safely reopen two of the three southbound lanes on Interstate 87 in advance of tomorrow morning’s rush hour,” DOT Region 1 Director Patrick Barnes said in a statement Wednesday night.

“Options for a more permanent repair to the structure are still being evaluated and the overpass will remain closed until further notice.” As of Wednesday night, the southbound Northway is open only to passenger vehicles between Exits 10 and 9, with trucks being directed to detour at Exit 10. Barnes said that to better accommodate local southbound traffic, the timing of traffic lights along State Route 9 have been adjusted for motorists using that alternate route.

There was plenty of frustration on the road with Wednesday’s situation.

As lines of traffic backed up in the immediate aftermath of the crash, state police turned vehicles around to get off at Exit 9, and they started diverting southbound traffic at Exit 10, farther north in Clifton Park. Entering the southbound exit ramps was blocked at both Exit 10 and Exit 11 at Round Lake.

The delays lasted throughout the day, making it perhaps the most extensive temporary Northway shutdown in recent memory. “I got stuck in it,” said Sarah Burger, a Saratoga Springs attorney who left that city at 2 p.m. and didn’t get to Latham until shortly before 4 p.m. “They took us off at Exit 10 and put us on Route 9, but Route 9 was completely backed up.”

Traffic backs up down Route 9 southbound in Jonesville Wednesday after a truck towing a trailer with a boom lift struck the Sitterly overpass on Interstate 87 southbound near exit 9 in Clifton Park. (Provided photo — Erica Miller, Daily Gazette)

Northbound Northway traffic was unaffected.

No injuries were reported in the crash, but photos from the scene showed structural damage to the Sitterly Road overpass — a sliced beam that raised questions about the condition of the bridge, which carries a county-owned road over Northway and is maintained by the state Department of Transportation. The bridge, used by around 15,000 vehicles per day, was barricaded to all traffic.

Photos posted to Facebook by the Clifton Park Fire Department showed three of the five steel beams under the bridge deck bent, and gouges in the Northway pavement caused by the boom rig having fallen off the trailer.

The damage to the bridge was located just below a final sign affixed to the overpass showing the overpass clearance to be 14 feet, 4 inches.

State police tweeted just after 11 a.m. that the southbound lanes would remain closed until further notice. The Exit 11 southbound ramp was also closed and the Sitterly Road overpass remained closed.

While incidents that close parts of the Northway are common enough that state Route 9 is a well-established detour, the level of traffic quickly overwhelmed that road as well as other alternative routes.

The Sitterly Road bridge, which links residential areas of Halfmoon to services at and near the Clifton Park Center mall, is also very busy for a local road, carrying more than 15,000 vehicles per day.