Emily Greenwood was run down by a cyclist. Credit:Edwina Pickles Or not. Within 20 seconds of Golf-club Guy's passing, there's the unmistakable sound of collision. I turn to see Golf-club standing, gobsmacked, and Bike Bloke on the ground – large, middle-aged, helmetless, red-faced, shouting. I stand, astonished. Which is when Bike Bloke starts on me. "And you, ya f-----g c---!" he roars, straight to full throttle. "You could've got outta the way! You're just a great big f-----g c---!" I explain politely that there was limited room on the path and rather a lot of room on the road, where he, a cyclist, belongs. "The road's too f-----g dangerous!" he bellows. "I can't cycle on the f-----g road!"

I inform Bike Bloke that it is possible. I cycle that same road, often, and so far without mishap. But Bike Bloke is unpersuaded. "You're such a f-----g c---!" he yells, unafraid of cliche or repetition. "Ya know that? F-----g c---!" He cycles off. I walk on. After a few second he returns. "You're Elizabeth Farrelly, aren't you?" he screams. I explain politely that there was limited room on the path and rather a lot of room on the road, where he, a cyclist, belongs.

I say this is irrelevant to the discussion in hand. "I thought so!" bawls Bike Man. "You really are a f-----g c---. Ya f-----g c---!" I exaggerate not. Indeed, I have omitted entire gobbets of the abuse, to spare you boredom. But it makes me wonder. Is there any solution? Should cycles, or cyclists, be registered? Would it have made any difference, in my case or in Emily Greenwood's, had registration been in force? I doubt that either Greenwood (unconscious on the footpath) or I (gobsmacked) would have had the presence of mind to whip out our smartphone and record the incident. But is that the only reason for registration?

There has to be a way of coexistence. I walk a lot, I cycle a lot, sometimes on footpaths. I have no allegiance either way, but feel strongly that both modes of transport should be encouraged – they make for better selves, better cities, better planet. So I resent that, in any pedestrian-cycle conflict, it's the dirty loud vehicle traffic that wins. Most cyclists stick to the road and designated cycle paths. Mostly, they obey rules and lights, although cycle lights are often dysfunctional, undesignated footpaths sometimes unavoidable and pedestrian crossings often the best and obvious way to cross. And since my Bike Bloke encounter I've begun taking note: about half the bikes on footpaths are careful and benign. It's the other half at issue here: impatient, intolerant, arrogant and rude. Interestingly, they tend also to disdain helmets, suggesting that they have no intention of ever hitting the carriageway. What to do? The pro-registration arguments are five. In order of plausibility: user-pays, safety, better statistics, accountability, and insurance. The user-pays argument, that cyclists should help pay for infrastructure, is the least persuasive, since roads and cycle-ways are built from general revenue, not some purpose-specific tax. It's called public infrastructure because we all pay, we all get to use it. This is an ICP. Important Civic Principle.

Safety? Well, there's no evidence, statistically, linking death to rule-breaking. I'd guess more cyclists are killed by other people's bad driving than their own. Statistic gathering? Well yes, of course, but by itself that is insufficient reason. Accountability is more compelling. I cannot see why cyclists shouldn't take responsibility for their behaviour, as motorists must. But would registration achieve that? We don't know. Of the five, the insurance argument is most persuasive. Emily Greenwood, several weeks on, is still uncompensated, still absent her front teeth. Compulsory third-party cycle insurance, as with motor vehicles, would relieve at least this inequity. Against cycle registration the argument is just one, but it is emotive and political. It pivots on the idea that registration, far from deterring misdemeanour, is a deterrent against cycling itself. Does this wash? We want people to cycle. Tick. We want as many people as possible to cycle as much as possible. Tick. Does this mean we must put up with whatever behaviour cyclists choose to dish out?

The anti-registration argument is expressly libertarian. So it's odd, especially within the ya-boo-osphere of Australian politics, that registration is seen as a rightist push (supported only by NSW Roads Minister Duncan Gay and Sydney City Councillor Christine Forster). But you can see registration as an attack on cycling, or you can see it as a defence of walking. This points to another ICP. Laws exist to protect the weak. On the road, cars are strong and cycles weak. On the footpath, cycles are strong, pedestrians weak. I don't know if registration would curb the bike bullies. It might. But I can tell you one thing. I'd pay cycle rego twice over if it brought Emily Greenwood new front teeth.