the majority of bike accidents is through idiotic car drivers mate

Surely if the bikers know about "idiotic" drivers (Which you hear no end of bikers banging on about) the would take into account the hazard and not ride at triple the speed limit everywhere?
like a friend of mine that nearly got knocked off when "i was doing 140 down the m1 when some stupid c*nt decided to change lanes!"....whos really at fault there?