A coroner, Ian Smith, wants hi-vis clothing made compulsory for cyclists. Christchurch cyclist and forensic pathologist Dr Martin Sage disagrees.

The recent discussion about cycling safety has been extended by Coroner Smith's proposed solution of hi-vis clothing for all cyclists. Unfortunately this attempted hardware solution for a software problem will not work.

The problem is drivers actually registering the presence of the cyclist they see and acting appropriately. There is a substantial body of academic research which separates "seeing" from "looking". A good place for readers to start if they are further interested would be The Invisible Gorilla by Christopher Chabris and Daniel Simons (2010).

No amount of gaudy apparel will remedy the failure of drivers to perceive the presence of cyclists, but increasing numbers of participating cyclists, sufficient to make them an ever-present and expected part of road activity, will very likely do so. The marked increase in the prevalence of cyclists on Christchurch roads in the last five years is very encouraging to me because this will increase car driver perception of us all.

I'm one of those Mamils (middle-aged men in lycra) some readers like to rail about but I do have 49 years of experience in commuting, recreational and competitive cycling, including more than 20 years in urban Christchurch and the surrounding rural areas.

It is also my sad task to examine at autopsy most of those cyclists and car occupants who are killed in road crashes in Canterbury and Westland so I have had plenty of opportunity to mull over these things. I am the senior author of the only academic review of the pattern of fatal injuries to cyclists in this country.

There are three important concepts I would like to contribute to the discussion on cycling safety:

1. Overtaking

2. The B-pillar phenomenon

3. Stupid safety

A few cyclists die at their own hand when losing control on steep descents, particularly on wet roads. A few more die by wrongly pushing their luck at intersections. A significant number die when drivers fail to give way to them at controlled intersections, some of which is clearly the perception problem of looking versus seeing.

Bear in mind that car drivers and occupants also get killed at these intersections when drivers "fail to see" and consequently fail to give way to other cars, trucks and even trains. Perhaps trains need hi-vis vests too?

My greatest concern is the significant and very worrying proportion of cyclist deaths that result when the bike is struck from behind, in broad daylight, on straight, wide roads by overtaking motor vehicles.

Congratulations Cantabrians: from my observations about 70 per cent of drivers get their overtaking manoeuvres exactly right in the rural and semirural roads around Christchurch. About 10 per cent get a bit carried away and feel the need to take their vehicle completely across white centre line to the other lane, which is okay, but does make me wonder whether they really know where the edges of the vehicle are in relation to the cyclist.

Another 10 per cent are more worrying. These are the ones that pass within arm's length and then subsequently move out to the middle of the road or the opposite lane after they have passed. I'm not sure whether these drivers just didn't get their range-finding right, or are reacting to having suddenly appreciated that they have come very close to running me down.

The last 10 per cent are the real worry. About 7 per cent pass within less than arm's length of my bike. Some seem adamant they will not put their vehicle even an inch over the white centre line, despite there being no oncoming traffic for more than a kilometre. On our rural roads, a bike riding at the sealed margin plus a car fills a whole lane without any wishful thinking about allowing a metre or metre and half gap between the two.

Although some drivers may not have perceived me at all, a smaller proportion of others clearly have, judging by the jeering and gesticulating of the youthful occupants who seem to be deliberately trying to scare the lycra bibshorts off me.

The last 3 per cent are very alarming: those who, as oncoming traffic, overtake into my lane while coming in the opposite direction to me, often passing within arm's length. This is a phenomenon I have only encountered in the last five years so and most (but by no means all) of the drivers are males in large SUVs.

I know they have seen me because any protests on my part are greeted by traditional hand gestures and verbal abuse. Virtually always their overtaking does not represent them going for a long-awaited overtaking opportunity gap in traffic, as there is usually a long empty road behind me, and had they waited another 15 seconds or so there would have been no hazard at all.

Having two tonnes of truck passing within arm's length of my head at a closing speed of 150kmh (my 30kmh and their 120kmh) isn't the level of risk I signed up for as a recreational cyclist!

The fun has only just begun when the front of an overtaking vehicle passes you as a cyclist. The B pillar is that part of the car where the front door frames sit just behind the driver's and front passenger's seats. It seems to me that a lot of drivers believe that cyclists simply evaporate once they fall behind the B pillar.

They certainly act that way, so that pulling into the kerb, turning left into a side street, or simply leaving no room at all between the passenger side of their car and the next parked car is commonplace. In fact, at most urban road speeds, this is far from the case. I'm often still sitting opposite your rear driver's window pulling faces at your child in their kiddy seat, and you risk a substantial panelbeater's bill when the 90kg combined mass of me and my bike thump into that part of your car.

Virtually all vehicles have left-sided wing mirrors these days - would you please check where the cyclist you thought you'd overtaken actually is before you run them off the road.

Coroner Smith wants hardware solutions to cycling safety. The one I want fixed first is the now fashionable "speed strictures". These strictures are presumably meant to slow motor traffic on the approach to hamlets, townships and important things like schools, but my observation is that they don't achieve that aim at all.

All they do achieve is unnecessary risk for cyclists. They have side traffic islands intruding on both sides of the road which push cyclists in towards the middle of the road and a painted "virtual traffic island" in the middle of the road between the two side islands which pushes road vehicles out towards the side of the road.

This inevitably brings the previously separate car and bike streams into space conflict and creates precisely the situation where cyclists are more likely to get struck from behind by overtaking traffic.

If you ride the very nice 40km stretch from Tai Tapu through to Leeston and back you have to pass through no fewer than 20 of these strictures - that's one every 2km. It is perhaps just as well the authorities recently removed the gratuitous "Share the Road" billboard in Old Tai Tapu Road which was ironically set about 50m short of one of these recently created hazards.

Rather than grandiose gestures to cycling safety with poorly placed billboards or hi- vis vests, the authorities need to drop the lip service and actually eliminate this sort of real hazard. I'm sure other cyclists could contribute their favourite bit of "stupid safety" such as "Works End" signs blocking cycle lanes. Let's make a list.

Keep cycling everyone - you are all helping to save my life by just being out there too.