The cold and ice that swept through southeast Louisiana Tuesday and Wednesday froze transportation networks, forcing the closure of roads, bridges, streetcar lines and the runways at Louis Armstrong International Airport.

As the sun rose and temperatures warmed to just above-freezing Wednesday afternoon, some services and facilities began to come back online, but officials warned residents to avoid going out if they could, and to exercise extreme caution if they had to be on the roads.

Portions of major highways remained closed at mid-afternoon Wednesday, including Interstates 10, 55, 310 and 610. I-10 remained closed between Slidell and Baton Rouge.

The Lake Pontchartrain Causeway was closed in both directions, though officials had reopened the right lane of the north-bound span with a speed limit of 45 miles per hour. Just after 3:30 p.m., officials opened the left lane of the southbound span, also with a 45-mph speed limit.

"The southbound bridge is more problematic," said Causeway general manager Carlton Dufrechou. "The water is not evaporating as quickly as we thought it would."

Dufrechou also said workers would closely monitor the bridge throughout the night as temperatures on the bridge remained near freezing and there was still significant ice in the crossovers.

Roads across the area were treacherous throughout the night. State troopers worked nearly 100 crashes, though few resulted in serious injury.

In Metairie, an eight-month-old boy was killed when the vehicle his mother was driving slid from an ice-covered bridge into a canal. The woman was rescued and remained in critical condition at a local hospital.

In Orleans Parish, a man standing near the scene of a previous accident on Interstate 10 near Franklin Avenue was run over when a passing vehicle spun out of control, knocking the victim from the elevated highway to the ground below. 

The New Orleans Regional Transit Authority had restored service on some bus routes, but streetcars and ferries remained shut down. The cold temperatures and precipitation froze track switches that help control streetcar routes and accumulated on the cars' power lines, RTA spokeswoman Taslin Alfonzo said. 

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The Canal St.-Algiers and the Lower Algiers-Chalmette ferries would remain closed until staircases and boat decks were clear of ice, Alfonzo added.

After initially closing runways due to icy conditions, Louis Armstrong International Airport notified airlines that they could resume normal operations beginning at noon Wednesday. Travelers were being urged to check any scheduled flights directly with airlines, as times may have changed.

By 2 p.m., the airport's schedule of departures showed a mixed bag of delays and on-time departures, with only a handful of cancellations.

The airport has also advised that officials were continuing to monitor the runway conditions as another freeze is expected for the area Wednesday evening into Thursday morning.

Throughout the day, there had been no indication that the airport itself would close, although many roads, interstates and bridges remained shut down.

Flights at Baton Rouge Metro Airport were also affected by the weather. On Wednesday, most flights in and out of Baton Rouge were canceled. At 11:30 a.m., a few flights later in the day were still scheduled. The airport advised travelers to check with their airline for the latest information.

Follow Faimon A. Roberts III on Twitter, @faimon.