Dbase abuse.. That's a little strange. Far as I know it's public info (the static ones at least)
Sure it may only list a stretch of road between two cross streets that they maybe positioned to be cautious of. But it's public.
I use to update the Garmin POIs with them and maintain the CHC mobile zones from zenbu - Until someone decided they didn't like the non introusive warnings of the mobile zones in their daily commute so deleted them
Christchurch has had a reprise since the quakes. And only the mobiles hang about while the statics out of town were replaced with the newer high ISO/faster models that don't need manual retrieval/moving around.
He maintains and updates the DB on his own dime as a hobby / supporter of the NZ radar detector users. He puts a lot of time and effort into this, he has previously provided these updates on a "donation" basis for his efforts. Some have taken his work, installed it on detectors and then sold for a profit, they used databases from detectors with different firmware and different serial numbers, reducing the effectiveness of the DB to the unwitting purchaser.
The information is indeed all public (he gets direct under an official information act request) but the programming and updating of detectors is above and beyond.