The issues at the two sets of traffic lights - at the intersections of Quarry and Gladstone rds and Gordon Rd and Hagart Alexander Dr - come after NZTA and the council made changes in an attempt to make them safer about halfway through the year.
Council senior traffic engineer Ron Minnema said both it and the NZTA were working to get to the bottom of the problem after receiving eight complaints since the changes were made.
''What's happening out in Mosgiel, we don't have one intersection, we have two intersections right beside each other, with a railway line in the middle.
''You don't get a lot more complex than that, so we have got a few issues there,'' Mr Minnema said. Issues included queues being too long, he said.
''The times I have been out there it has been fine, which makes me think there are some intermittent issues that are going on.
''We have also had a problem with one of the detectors as well, which hasn't helped,'' he said.
Mr Minnema said some problems were also caused by the public's behaviour.
''Like, shall we say, everyone leaving at 8.50am when they want to get to work at 9am. If some of them left at 8.45am and 8.40am there would be absolutely no issues at all,'' he said.
The council will update the Mosgiel Taieri Community Board about the issues in January.
NZTA senior road safety engineer Roy Johnston said it had remedied one source of problems in the past two weeks.
''We are aware that there have been some teething issues with the operation of the signals, as software hasn't functioned as intended. These issues were finally resolved. It was now monitoring the intersection to see if there were other issues.
That would include the extent of traffic queuing during peak morning and evening travel times, to see if it was a significant problem and implement a solution.
