PORTLAND, Ore. (KOIN) — An operator for Portland Streetcar has tested positive for COVID-19, the company announced on Tuesday.

The operator has reportedly been self-quarantining since learning a family member of theirs tested positive on Friday. Portland Streetcar said that all streetcars and facilities the operator had been in recent contact with were thoroughly cleaned and sanitized. They also said that operators have been required to keep their cab doors closed while in service for months in order to help mitigate the spread of the virus.

Citing public health experts, Portland Streetcar says that public transit is considered to have a “relatively low risk for virus transmission when adhering to illness prevention guidelines.”

The transportation company will continue to implement the safety measures already in place, including a mask requirement for riding, a limit of 23 riders per car, social distancing both on-board and at stops, as well as sanitizing each streetcar every four hours.