The speed limit on a 3.5-mile stretch of State Route 109 south of Seabrook will drop from 50 to 40 mph as early as Tuesday, June 30, the state Department of Transportation announced Monday.

Crews will install new 40 mph speed limit signs between mileposts 23.2 and 26.9. The existing posted speed limit between mileposts 21.6 and 26.9 has been 50 mph. State Route 109 between mileposts 21.6 and 23.2 will remain at 50 mph.

The speed limit changes are the result of a recent Department of Transportation engineering study, according to the agency statement. The lowered speed limits will be enforceable as soon as new signs are posted.

For information on how the state sets speed limits, visit www.wsdot.wa.gov/travel/operations-services/speed-limits.