(CHICAGO) Riders can expect delays on Metra’s BNSF Line for the next three weeks as the transit agency works to replace more than 10,000 ties along nearly 23 miles of railroad.

The project, which started Saturday and will last until Sept. 16, will replace worn ties between Roosevelt Road in Chicago and west suburban Lisle, according to a statement from Metra.

While most of the work will occur at night to minimize the impact on train service, speed restrictions in the constructions zones will cause delays of five to 10 minutes for some rush hour and evening trains, Metra said.

The work is part of an approximately $1.5 million Metra construction program which includes about $200 million in infrastructure improvements to 27 stations, 21 bridges and 24 road crossings in addition to the replacement of 120,000 rail ties, Metra said.

“This is the type of maintenance that must be done on a continual basis so that we can maintain the track speeds and service levels our customers rely upon,” Metra Executive Director and CEO Don Orseno said in the statement.