A clear winner has emerged from Santa Rosa's one-month trial of two rival manufacturers of high-tech parking meters.

There's just one problem — it's going to cost the city even more than expected to roll out the new technology downtown.

The pilot project in the 600 block of Fourth Street downtown clearly showed that IPS Group of San Diego was the favorite of the public and city staff alike, besting Duncan Solutions of Milwaukee, said Kim Nadeau, the city's parking coordinator.

Drivers preferred IPS's larger, easier to read screens while city staff reported they were easier to maintain and empty of coins. It was also easier to spot meter violations.

But while the units were well received by the public and staff, people spent 9 percent less using the meters over the 30-day trial period than they had the prior year.

"I was very surprised," Nadeau said. "I didn't think we'd see a 9 percent revenue decrease."

That means that in addition to spending $258,000 to expand the program to 219 meters over six downtown blocks, the new meters will probably mean about a $55,000 drop in annual meter revenue, Nadeau said.

"There is a cost associated with that convenience and this is the cost," Nadeau said.

The recommendation heads to the City Council on Tuesday.

It's possible drivers using the new single-space meters spent less than the kiosk-based system because people using the kiosks were willing to buy more time knowing they could take it with them, Nadeau said.

The walk-up kiosks, which many people considered inconvenient because it required them to walk back to their vehicles to put a slip of paper on their dashboards, allowed people to use the time they purchased anywhere in the downtown parking district.

The single space meters, however, leave any remaining balance on them. This benefits drivers lucky enough to find money already on the meter but results in a revenue loss to the city. Sensor technology that zeroes out the meters when a car leaves turned out to be too expensive to be cost effective and had reliability issues during the test, Nadeau said.

Another reason for the revenue drop may be because there was a 20 percent drop in credit card revenue compared to the kiosks, and credit card transactions on average are higher, Nadeau said.

Bernie Schwartz, owner of California Luggage on Fourth Street, orchestrated the petition drive by downtown merchants that prompted the city to undertake the pilot.

"As a merchant, I'm grateful to the city for moving forward on this," Schwartz said.

He said it was premature for the city to assume a revenue drop from the new meters, calling the test period too short for such an extrapolation.

They've definitely delivered on their promise of being more user friendly, he said. Since the meters have been installed Schwartz said the steady stream of complaints he received from his customers about the kiosks has abated.

"It's hard to put a price on customer satisfaction," he said.

(You can reach Staff Writer Kevin McCallum at 521-5207 or kevin.mccallum@pressdemocrat.com. On Twitter @citybeater.)