Aepervius
Non credunt, semper verificare
If you let the cat outside when it is young, it will want to go outside. There are two solutions : 1) never let it go outside. Works relatively OKish, even after a while they don't even try to go outside on their own. 2) use a leash from start. This one is hit and miss.
Keep in mind that a cat as pet live very long, compared to cat in the wild. If I recall correctely, a feral cat has a live expectancy of ~4 years , whereas compeltely indoor pet cat live 10+ years (except when you are called creme puff : http://en.wikipedia.org/wiki/Creme_Puff_(cat) ). So 6 years is not that bad , but you would be better off with a good barrier to the road , or keep the cat indoor.
Keep in mind that a cat as pet live very long, compared to cat in the wild. If I recall correctely, a feral cat has a live expectancy of ~4 years , whereas compeltely indoor pet cat live 10+ years (except when you are called creme puff : http://en.wikipedia.org/wiki/Creme_Puff_(cat) ). So 6 years is not that bad , but you would be better off with a good barrier to the road , or keep the cat indoor.