While the New Zealand Transport Agency (NZTA) say it's too early to have collated data on the number of crashes that have occurred since March, the new speed limits have been roundly welcomed.
"We have seen a reduction of offending over the past five months as the driving public becomes aware of the new limit, and I think understands why it has been introduced," says Canterbury road policing manager Inspector Al Stewart.
He cited research which shows the chances of a pedestrian or cyclist being seriously injured or killed when struck by a vehicle travelling over 30km/h increases significantly.
"As the inner-city heals and we see an increase in road users coming back into town, we will also see an increase in the potential for crashes," Stewart said.
"As a prevention based organisation we need to be thinking ahead with our road safety partners and identifying opportunities to mitigate these risks. The reduction in the inner-city speed limit is an example of this."
Christchurch City Council's manager of transport operations, Steffan Thomas agreed.
He said "most road users" are supportive of the move and have stuck to the lowered limit.
The Cycling Action Network (CAN) has lobbied strongly for lower speed limits in New Zealand city centres.
Over the last decade, 15 suburban centres in the Wellington area have opted for 30km/h zones.
"Tellingly, there have been no campaigns to return to 50km/h," says CAN spokesman Patrick Morgan.
Lower CBD speed limits create more attractive and liveable centres for cyclists, pedestrians and business owners, he said.
"It is the gold standard and we'd like to see every city in New Zealand adopt that approach," he said.