Problems with control room equipment are causing major disruption on Nottingham's tram network.
Services to Hucknall are terminating at Bulwell and passengers travelling to Phoenix Park are being advised to use the park and ride at Wilkinson Street.
Timetables have also been affected, said Nottingham City Transport.
Although the disruption was more widespread earlier, the current problems are likely to last until the end of Monday.
Replacement bus services have been put in place while engineers try to find the cause of the problem.