"I think people largely ignore the stop sign. They all just roll right through."
From cars hitting the kerb, to drivers going through the front of the RSA building, he said they had "shared in almost every one".
"Some have been quite severe with serious injuries."
Williams said there appeared to be some confusion when there shouldn't be.
"You would think Hastings St is the principal right of way compared to Vautier St which is a secondary street.
"You have to physically stop."
He said there was also an issue of people assuming those who were stopped were giving way in relation to an old road rule - left-turning vehicles gave way to right-turning vehicles - which has now been retired.
He supported the idea of a roundabout and thought it would be "beneficial".
"Napier and roundabouts go hand in hand - they are everywhere.
"Generally people are more conscious about what goes on in a roundabout."
Council will install a temporary roundabout as part of a three-month trial to improve both traffic flow and safety at the intersection.
Team leader of transportation Robin Malley said council was aware the intersection had a history of crashes.
Video monitoring was conducted over one day after a council officer witnessed a cyclist travelling down Vautier St being struck by a car that did not stop, resulting in the cyclist being taken to hospital.
"There are frequent crashes which are not reported but are witnessed by council staff due to the location of some of the Council offices in the Cape View building, which overlook this intersection."
He said about 68 per cent of the traffic came from Hastings St - of those travelling north only 6.3 per cent stopped while 8.1 per cent of those travelling south did.
Malley was also concerned about motorists approaching the intersection from Marine Parade - many who were seen to be travelling between 42 km/h to 45 km/h.
"This is not appropriate for an area where there are many pedestrians, motorists parking or pulling out of driveways, and plenty of cyclists."
The temporary roundabout will cost about $10,000 and will be installed on Monday.
Further monitoring will be carried out following this.