Research critical of parking sensors

New research has cast doubt on whether Wellington’s parking sensor technology is completely reliable, as fresh figures show some sensors are continuing to wrongly ticket motorists.

Between January and November 2017, the capital’s sensor car parks issued 1519 incorrect tickets – ranging from 88 to 198 errors a month.

In December, the council put this down to ‘‘teething’’ problems, saying the incorrect fines stemmed from some sensors not resetting when a car entered or left a park. But the issue has not improved. In December and January, the total number of sensor errors was 171 and 125, respectively.

The latest figures come as a research paper by Australian parking consultant Glenn Caldwell – published earlier this month – casts doubt on the reliability of sensor parking technology.

The paper questions the sensors’ ability to maintain accurate readings over their lifecycle, and claims infrared is not a viable solution for in-ground sensors.

‘‘Infrared solutions use a secondary technology to crosscheck reading accuracy,’’ Caldwell said in his report.

Wellington City Council’s battery-powered parking sensors use both infrared and magnetic technology. Peter McLellan, the council’s parking services manager, said it had paired the two technologies to improve their overall performance.

But Caldwell’s research says sensors that use dual technologies were running an inferior solution to offset the weakness of another inferior solution. They were likely to consume battery power, and were also expected to fail sooner, the report said.

Caldwell also claimed the sensors did not always accurately detect when a vehicle had left the parking space, causing an error. Detectors were compromised by the presence of chewing gum or build-up of dirt, his report said.

Wellington now has about 3500 parking sensors across the central city, after rolling out this system between August 2016 and November 2017.

McLellan said there was only one sensor error in every 1600 transactions.

‘‘Compared to the examples in the study, this is a very low error rate,’’ he said. ‘‘All the same, we understand how it affects customers and we’re working to minimise any inconvenience.’’

‘‘Compared to the examples in the study, this is a very low error rate. All the same . . . we’re working to minimise any inconvenience.’’ Peter McLellan, Wellington City Council parking services manager

Since December, the council had made changes to allow any staff member to be approached on the street by the public about a possible error. Previously, staff could only advise customers to follow the council’s standard appeal process.

McLellan rejected the idea that parking sensor reliability could worsen over time. ‘‘The software platforms have alarms in place to support the sensors and advise the operator of any issues.’’

Wellington’s sensors had a fiveyear lifespan, he added. ‘‘Near the end of the council’s five-year agreement, a review will be undertaken to assess the current performance, as well as identifying new technologies available.’’

McLellan said the system was meeting the council’s expectations, and it was not losing revenue from having to refund parking fines.