Fairfax columnist Bruce Guthrie reckons there’s a case for compulsory registration of bicycles. He thinks rego “might at least begin to heal the rift between riders and motorists” by making cyclists more accountable for what he sees as their poor on-road behaviour.

The key downsides of registration are clear enough. It would impose an ongoing financial burden on households, it would very likely be a deterrent to cycling, and it would require considerable resources to administer. The politics are so horrendous it’s not likely to happen anyway (there are just too many households with multiple bicycles), but what I’m interested in is whether or not it would be good policy.

The theory is that registration would enable errant cyclists to be traced via their licence plate and justice meted out, but I’m hard pressed to see what the tangible benefits would be. Speeding is the most common traffic offence, so licence plates mean motorists captured on speed cameras can be tracked down, but speeding has very little relevance to cyclists. So the benefit of bicycle licence plates is massively diminished.

Most other traffic offences, such as failing to halt at a stop sign or driving under the influence, aren’t detectable by remote cameras. You have to be caught committing the offence by police who’re on the spot. In that situation the police are only interested in the identity of the driver or the rider, not the vehicle. So again, licence plates for bicycles would have little relevance.

People sometimes say they’d like bicycles to have a licence plate so they can report poor cyclist behaviour to the police. The trouble with that is police can’t and don’t do anything about reports they can’t corroborate. That holds for motorists and it would hold for cyclists too.

What the case for licence plates mainly comes down to is a single situation — red light cameras. Yes, many cyclists do ignore traffic signals, but deterring offenders hardly seems enough of a pay-off to warrant a major bureaucratic undertaking like a registration system. There aren’t even that many cyclists compared to other road users — cycling only accounts for around 1% of all passenger trips.

There’re also some practical issues. The vast majority of signalised intersections don’t have cameras. It’s questionable if the cameras could even read the sort of small licence plate that would be feasible for a bicycle.

In any event, it’s pertinent to ask what the benefit of trying to prevent cyclists from ignoring red lights would be. When a motorist runs a red light — a common occurrence in my experience — he potentially endangers others. When a cyclist deliberately runs a red light, for all practical purposes she only endangers herself.

Cyclists actually rarely run red lights — it’s simply too dangerous for their health. What they mostly do is cross against the red, but only after they’ve taken the precaution of seeing that there’s no danger. It’s an unlawful but calculated decision. Very few cyclists are killed or seriously injured by this practice, so the public benefit of registration in terms of avoided health care costs is doubtful.

I can’t see how motorists would be better off if cyclists were prevented from ignoring red lights in this way — in fact drivers might even benefit from cyclists crossing against the red if it means cyclists clear the intersection quicker. Some motorists could get psychic value from bicycle registration, but it sounds like spite (which isn’t to say there aren’t other offences by cyclists that impact negatively on drivers, but the issue is whether or not they would be mitigated by bicycle registration).