It was relatively common to pull over a speeding driver about every five minutes, she said, especially in fine weather when people tended to speed more.
The high concentration of pedestrians in the inner-city presented speeding problems other areas didn't face, Mr Clement said.
"There's such a huge number of pedestrians here. We have a disproportionate number of pedestrians ... that are hit and killed. And the consequences of getting hit by a car travelling at 65km/h as opposed to 50km/h is huge.
"Of the seven fatalities we had this year, three of them were pedestrians - and that's not matched anywhere else in the country."
This year to October, seven road deaths were reported in the Auckland City district. In all but one of those, speed was recorded as a factor in the deaths.
The three pedestrians killed make up almost 43 per cent of the road toll in the city this year, while the pedestrian road toll nationally is just 11 per cent.
Mr Clement said he personally hoped the 4km/h tolerance would eventually become the norm.
"It's about making the roads safer. If everybody bought into it and monitored their speed there would be far fewer crashes and far fewer fatalities. Every kilometre that you step it up, the survivability of a crash is greatly reduced.
"There were 57 fatalities [nationally] last December-January. If we can reduce that by seven, or 10 or 27, that would be significantly less trauma in the community. The cost of fatalities to society is hellish."
A common reason extolled by speeding drivers caught this month was Christmas stress, he said.
"When you stop people you can almost guarantee that they'll say they're busy people and this is a busy time of year. But we've just got to get them to stop."
But the cost of being too busy to check your speedometer could end up hurting, Mr Clement said. The faster the speed, the higher the penalty.
"And that'll be one less Christmas present you'll be able to afford."
High-risk death spots
• Ellerslie-Panmure Highway (between Burt Rd and Ballarat St).
• 1136 Great North Rd, Pt Chevalier.
• Church St, Onehunga.
• Mt Albert Rd, Three Kings (between St Andrews Rd and Rowan Rd).
Radar hotspots
• Tamaki Drive.
• Quay St.
• Great North Rd.
• New North Rd.
• Hillsborough Rd.
Sorry officer
• I was running late for work.
• I was racing to catch the lights.
• I wasn't aware of the speed limit.
• I was just in a hurry.
• I'm late to pick people up.
• I just wasn't paying attention.