Police said the incident occurred at about 4:36 a.m. in the outbound lanes of the expressway near 87th Street.
No injuries were reported, police said.
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The police activity forced all traffic in the outbound lanes off the expressway at 83rd Street. Shortly before 7 a.m., all lanes reopened to traffic.
A gaper's delay also caused delays in the inbound lanes of the Dan Ryan.
Further details were not immediately available.
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