The state Department of Transportation will reduce part of Interstate 81 in Cicero to two lanes for at least six months to replace a culvert as part of the massive project to remake I-81 and I-481.

Construction begins at 9 a.m. Monday and could last until late October, according to the DOT.

I-81 will be reduced to two lanes of traffic in each direction and northbound traffic will cross to southbound lanes in a stretch south of the northern interchange between I-81 and I-481. Lanes will be reduced from the interchange to the South Bay Road bridge in Cicero.

Also starting Monday, the following ramps will be closed:

• Exit 9S (I-81 southbound) entrance ramp from I-481 northbound to I-81 southbound.
• Exit 9N (I-81 northbound) entrance ramp from I-481 southbound to I-81 northbound.

Drivers should follow detour signs.

The detour from Exit 9S will take drivers to Exit 10 (Route 11 Circle Drive North Syracuse), to eastbound on East Circle Drive, to southbound on Frontage Road, to southbound on South Bay Road, to westbound on Bear Road, to State Route 481 southbound, to I-81 southbound.

The detour from Exit 9N will take drivers to Exit 8 (Northern Boulevard), to eastbound on Northern Boulevard, to I-481 northbound, to Exit 9N (I-81 northbound).