Two abrest simply makes it HARDER to pass and MORE likely to get hit. It also forces vehicles into oncoming traffic.
Allow me to quote myself: "Most cyclists, and certainly the ones I ride with, are sensible about this: if it's only one lane in each direction, for example, we'll drop down to single file." I cannot speak for all cyclists, obviously, but every time I've seen cyclists riding two abreast, it's been on roads where there are two, or even three, lanes available to traffic heading in a given direction (i.e.: four, or six, lanes total.) Two abreast only makes it harder to pass in these conditions (as you assert) if traffic is very heavy, or the driver is not planning ahead. In the former case, the odds are pretty good that passing the cyclists is going to save three quarters of stuff all time. In the latter case, well, there's no help for drivers that aren't thinking ahead in general, cyclists or no.
As for forcing vehicles into oncoming traffic - do level crossings force cars into risking a collision with a freight train whenever the boom gates are down and the lights are flashing? Do red traffic lights force cars into risking a side-on collision when they enter the collision? Drivers have an obligation to drive to the conditions; if it isn't safe to pass, the onus is on them to sit back, relax, and wait for an opportunity.
Why does everything have to be done NOW NOW NOW NOW NOW GET OUT OF MY WAY I HAVE TO BE THERE TEN MINUTES AGO? Like I said - relax, and take things as they come; it makes life far less stressful in general.
Here's an idea: you want to be VISIBLE? GET A DAMN FLUORO VEST AND LED LIGHTS. AND MIRRORS. AND A BELL
I do have lights, and use them (matter of fact, I have a Fly6 on order to replace my rear light for my commute; Google it if you're curious). Mirrors aren't worth the space: a head check is more reliable, and is a very visible signal to drivers around me (if they have seen me) of my intentions - last time I tried to put a mirror on my commuting bike, the damn thing kept moving out of position, and it vibrated so much, I couldn't see anything in it even when it was in position. A bell? Do you know just how heavily soundproofed modern cars are? A standard bicycle bell, of the type that's sold standard, is not going to penetrate.
Either we are too tough on motorbikes or too soft on push bikes.
Consider the speeds and weights of the typical motorbike, and the typical bicycle. A motorbike is frequently travelling at speeds of up to (or over!) 100 kph. A cyclist? Well, I usually push around 30 kph on the flat. Some of the fitter guys in my triathlon club push 40 kph on the flat. It's not until you hit the really elite levels that you're likely to find people who can consistently do 60 plus kph. A cyclist generally weighs somewhere around 100 kg with the bike; a motorbike is anywhere from 250kg up; add in the rider, and you're looking at a minimum of three times the mass of the cyclist.
Kinetic energy equals one half mass, times the square of the velocity. So a motorcyclist can easily have around 20 times the kinetic energy of the cyclist - it's absolutely reasonable that a motorcyclist wear more protective gear than the cyclist (and even then, you can argue that the motorcyclist isn't doing enough to protect him/herself.) And hey, there've been more than a few times that I've seen motorcyclists wearing nothing but jeans and a T shirt, and a helmet. The words for people like that are "organ donors walking".
It's all about the level of risk, versus the return of protecting against that risk, versus the cost of protecting against that risk. There's only so much that society should be legislating in favour of; beyond that point, you're going to discourage a form of transport that is cheap, effective, and (generally) healthy. The sorts of protective gear that you're implying cyclists should wear, IMO, go beyond that point. (And yes, I freely admit that this is my opinion; society is well within its rights to make a considered choice that differs from it. So far, that hasn't been the case.)
