[nicky g]

"3) with the exception of excessive speeds, speeding can be much more easily reasoned as not dangerous (and possibly true) and is widely accepted as not very dangerous, whereas drugs are widely accepted as dangerous."

I disagree, especially depending on what drugs. Furthermore, the people who take those drugs are only putting themselves at immediate risk in health terms (they may be indirectly putting other people at risk due to teh possibiolity of addiction and having to turn to crime or whatever, but that's mainly a consequence of the illegality of the drugs), while the speeder is putting other people at increased risk.