It's a device that measures one of the most contentious distances in Australian road safety – the amount of space between a bicycle and an overtaking car.
Called the C3FT, it has an ultrasonic sensor mounted on the bicycle's handlebars to calculate how near the vehicle came to the bike.
Use of the device was pioneered a year ago by police in Chattanooga, Tennessee, a city that has a three-foot buffer law when drivers overtake cyclists – similar to the metre and 1.5-metre passing measures now found in half of Australia's states and territories.
"No matter how fast [the car] is going by, it even catches the rear-view mirror," Officer Rob Simmons told Ars Technica.
Dressed in regular clothing, with an HD camera mounted on the bike and a readout indicating lateral distance, Simmons is able to measure close passes – and sometimes catches up with a vehicle in traffic to speak with the driver, or radios ahead to a colleague.
This week, a Chattanooga Police Department spokesman told me their Safe Biking Initiative – of which the C3FT is a part – was contributing to improved relationships and safety on the road.
The program "is about high visibility and education, not tickets," the spokesman told me. "Most citations are issued as warnings at this time."
Christopher Stanton of Codaxus, the company that makes and sells the C3FT, says the device is now being used by more than half a dozen organisations, "primarily for education and outreach but with some enhanced enforcement activities … these activities provide wider exposure of the law and the reasons for its existence".
This week, Phoebe Dunn of the Amy Gillett Foundation – which campaigns for "metre matters" laws – told me the AGF is intending to utilise the C3FT "in a collaborative research project to measure passing distances in Victoria".
Is it enforceable?
But what about enforcement? The question of whether police are able to successfully fine motorists for breaches of the minimum distance passing law has been a controversial issue ever since the initiative was trialled in Queensland two years ago.
The measure has now become law in the sunshine state after an evaluation by CARRS-Q found that the regulations had improved motorists' awareness of bicycle riders. However, very few tickets were issued, and many cyclists expressed frustration that not enough was being done to promote the law.
Enforcement is also a point of controversy in New South Wales. In March, a suite of new cycling measures were enacted, including minimum passing distance laws and increases of up to 500 per cent for some cycling fines.
After two months, a Fairfax Media report showed a 56 per cent increase in fines issued to cyclists compared with the same period in the previous year, with helmet fines making up two-thirds of the 1545 infringements.
Meanwhile, four drivers had been fined for close passing.
Last month, representatives from Bicycle NSW, the AGF and Cycling NSW met with NSW Police and Centre for Road Safety officials to discuss concerns about how the new laws were being implemented.
Several key outcomes were agreed, including the need for better and increased publicity of minimum passing distance laws, and that police would review video evidence of possible law breaches (a signed statement would be required).
Police also agreed to run compliance campaigns for minimum distance passing distances and to evaluate new technology to help monitor compliance.
Assistant Commissioner John Hartley acknowledges the difficulties of enforcement, and while all 560 NSW patrol cars are equipped with cameras, he says the best way to issue an infringement was if a police officer witnessed an offence.
"But we're not able to be everywhere all the time, so probably 99.9 per cent of the time we won't be where it happens … but it's a great road safety initiative and we'll support it where we can."
I asked NSW Police about the C3FT device, and was told: "Senior officers from the Traffic and Highway Patrol command have looked at the technology and deemed it unsuitable as an enforcement tool. The use of this technology as an education tool is not considered appropriate for the NSW Police Force.
"However, we encourage the efforts of cycling advocacy groups to promote road safety through whatever means they choose."
A Queensland Transport and Main Roads spokesperson said: "TMR are currently working with the Queensland Police to investigate and trial technologies that might assist in accuracy and practical application in enforcement."
Of course, there would be a host of factors to tackle with an emerging technology such as this, including accuracy and issues of legality.
Nevertheless, the AGF's Dunn is excited about the possibilities. "Calibration would be the first step for any agency using C3FT or any similar device. And just like any other device (eg speed camera, breathalyser) they would need regular testing to ensure they are maintaining that accuracy."
The matter of a metre
Meanwhile, an inquiry is being held into whether Victoria should adopt the laws now in place in other states, with police saying they were concerned the measure would make roads less safe while being virtually impossible to enforce.
The TAC's senior manager of road safety, Samantha Cockfield, said: "The biggest concern for us all is that introducing a law where people can't always easily comply may bring about more tension in a system where there is a lot of tension already between motorists and cyclists."
Perhaps some of those tensions might be eased through education about the importance of keeping a safe distance when overtaking a cyclist - even if it takes a bit more time and patience.
So it'll be interesting to see what information the AGF's C3FT project might yield.
The concept is in its infancy, and may come to nothing, but other road safety technology we now take for granted – radars, breathalysers and red-light cameras – also had to start somewhere, and can still be a cause of controversy today.
Should a device such as the C3FT be used in Australia? Would you support its use to provide feedback to drivers, or to issue fines? Let us know in the comments section.
Fairfax journalist Michael O'Reilly has written the On Your Bike blog since 2011.