"Since the start of the pandemic nearly two years ago, we've worked tirelessly to provide the essential transit service that the region relies on. When Chicago needed us the most, we were there, providing as much service as possible," the agency said in a statement Sunday.
Like other transit agencies, some local employees have been unable to come to work because of quarantining or isolating due to COVID, the CTA said.
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Whenever an employee must call off work due to illness or self-quarantining, it can temporarily affect the schedule of buses and trains. Some scheduled trips may not occur, meaning there may be longer wait times for a bus or train.
The CTA also has a workforce shortage, the agency said.
"We are actively recruiting workers to fill existing vacant positions," it said.
The CTA apologized to residents for the issues.