A crash slowed traffic on the outbound Dan Ryan Wednesday afternoon.
A semi truck jackknifed in the express lanes near 35th St. after 4:30 p.m., causing massive delays and lane closures.
Only one express lane was open at 5 p.m., and traffic was backed up on the Dan Ryan all the way from the Kennedy south to the crash at 35th St.
Authorities have not released information on the cause of the accident, and continue to investigate. No injuries were reported.
Drivers are advised to use local lanes or Lake Shore Drive if possible.