An Iowa bus driver suspended for refusing to drive a bus displaying an atheist ad has returned to work this week.

Angela Shiel chose not to resign after her suspension but instead opted to return to her current position with the Des Moines Regional Transit Authority (DART).  

Still, DART has offered no guarantees that she won't face the same situation again. Bus assignments are made on the spur of the moment and are dependent upon factors such as the number of seats and mileage, DART general manager Brad Miller explained. 

"'We're giving her a second chance," said Miller. "There's no assurances that there might not be another ad she doesn't agree with. There's so many different things that go into that, there's no way we can guarantee anything." 

Shiel has indicated that should she be faced with the offending ad again, she would still refuse to drive the bus. And if she does, she will be terminated, The Christian Post reports.

"Hopefully I won't get the sign anymore," she told the Des Moines Register. "It's a chance I have to take. …I like what I'm doing. I don't want to start all over."

The buses will continue to run the ads through the second week of September.