Indiana State Police said that at about 4 a.m., a truck lost a load of tar on the ramp from northbound I-65 to westbound Interstate 80/94 near Gary. The tar is covering the two right lanes, but traffic can get by in the left lane, police said.
State police said it's not immediately clear how the tar spilled, as there was no crash.
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The ramp may be partially blocked for several hours.
As of about 6:30 a.m., northbound I-65 was backed up from Ridge Road to the I-80/94 and I-65 split.