Chopper 7 was over the scene at about 6:45 a.m. on northbound I-57 at 159th Street.
By 7 a.m. it appeared that firefighters had the blaze under control.
It was not clear what started the fire.
Illinois State Police said the fire started at about 5:48 a.m. and no injuries were reported.
The company debuted the "Maxxinista Express" over the holidays.
The bus was heading to Chicago on Wednesday to begin Mother's Day celebrations.
A TJ Maxx spokesperson released the following statement:
"The Maxxinista Express experienced a fire this morning. The bus had no passengers, and we are relieved to confirm the driver was unharmed. We are grateful for the support of emergency services, who responded promptly to contain the situation."
"We will be continuing our Mother's Day shopping event and are excited to greet the Maxxinistas who have been selected for the day's experience."
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