A Freedom of Information request showed that the council made a minimum of £190,060 and a maximum of £380,120 in motoring fines.
During the six month trial the roads were only closed to school-run parents and the council used automatic number plate recognition to ensure locals could use the roads.
Parents were given the chance to pay a discounted fine of £65 if they paid within 14 days.
Croydon Borough Council confirmed that as parents became used to the restrictions fewer fines were handed out.