It will be a sea of green-clad runners taking over Tom McCall Waterfront Park, Southwest Naito Parkway and various other streets on Sunday morning for the annual Shamrock Run. Estimates place the number of participants at around 25,000. There are several courses and the first run kicks off at 8 a.m. Officials will begin to close streets about 6:30 a.m. and the event should wrap up at 1 p.m.

TriMet expects many runners and others will use buses and MAX trains to make their way to Waterfront Park. If you normally use TriMet on a Sunday morning, expect crowds. Many bus lines will detour along the race routes. Check your bus schedule for any delays or closed stops. www.trimet.org

Half marathon route for Sunday's Shamrock Run, March 17, 2019.

Drivers will see delays and detours downtown and also southwest of town on Southwest Barbur and Terwilliger boulevards and on Capitol Highway. To avoid delays and detours, use another route into or out of downtown.

For a complete schedule of events and to view all course maps, visit the website for the Shamrock Run.

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DELTA PARK 8:33 a.m.: Crash on the ramp from I-5 northbound to Marine Drive.

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MAX BLUE LINE 8:10 a.m.: TriMet reports MAX Blue line to Gresham is experiencing at least 15 minute delays through 8:45 a.m. between Gateway Transit Center and Cleveland Avenue Station due to an earlier mechanical issue.

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BROOKS 7:31 a.m.: Crash reported on I-5 northbound near the Brooks exit north of Salem.

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MILWAUKIE 7 a.m.: Clackamas County reports Aldercrest Road is closed until further notice between Southeast Rusk and Oatfield roads for a road obstruction, possible water across the roadway.

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In east Multnomah County, Southeast 302nd Avenue is closed to through traffic between Division Drive and Pipeline Road for a stalled semi blocking the road. Crews expect to have the road reopened about 8 a.m. on Friday. Use Southeast Troutdale or Oxbow roads as alternate routes.

Update 8:12 a.m.: Reopened.

Coming on Monday: Work needed to repair joints on the ramps from U.S. 30 to I-405 will close lanes during the day and require some full nighttime closures beginning Monday, March 18. The Oregon Department of Transportation says in addition to the joint work, new concrete surfaces will be installed near the replaced joints and on three sections of freeway ramps. Detours will be posted.

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