Construction starting Friday will close lanes of Interstate 5 and ramps in Lakewood.
Crews will install data loops in the pavement of the freeway to measure speed and traffic congestion.
Northbound I-5 will be reduced to two lanes in Lakewood at 10 p.m. Friday, and the Center Drive onramp to the southbound freeway will close at 11 p.m. Everything will open by 6 a.m. Saturday.
Southbound I-5 will be reduced to one lane Wednesday at 11 p.m., and that lane will be redirected via the Thorne Lane interchange. Everything will open at 4 a.m. Thursday.
Any rain forecast would reschedule the work.