A second deep shaft is being dug at Avondale and Lavergne avenues as part of the next phase of the project to replace the Lawrence Avenue sewer in Jefferson Park. View Full Caption DNAinfo/Heather Cherone

JEFFERSON PARK — Montrose Avenue, which has been closed from Cicero to Milwaukee avenues since May, reopened to traffic Thursday afternoon, several days ahead of schedule, officials said.

Crews have finished connecting local sewers underneath Montrose Avenue at Lavergne Avenue to to the city's Deep Tunnel sewer and reservoir system in an effort to reduce basement flooding in Jefferson Park, said Ald. John Arena (45th).

In a message to 45th Ward residents Thursday afternoon, Arena thanked Jefferson Park and Portage Park residents for their "patience as crews performed this important work."

The closure snarled traffic throughout the area, sending drivers desperate to avoid the gridlock speeding down side streets and alleys. While police stepped up patrols and city crews laid speed humps across side streets, the traffic chaos continued, residents said.

The entire $20 million project to replace a 100-year-old sewer is expected to be completed by December, with crews working until midnight and Saturday to stay on schedule.

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