Govenor Linden's Roads

I have tried to ride my various vehicles on the beautiful highways in SL. I have never been able to rez the vehicle on the road and I always get the message that 'objects cannot be created here'! presumably because the permission is withheld
Why is this? Do I have to find an adjacent bit of land which does allow me to rez? If so where are they?

I might assume the roads are reserved for Gov Linden to cruise past in his stretch limo to view the peasants at work, but LL are more liberal than that surely?

Or is it just that I need a licence?

Aw, you don't need a license or special permission, but you do need to rez off-road and then drive on.

Also, there is a special place to rez your vehicles near Busy Ben's in Oak Grove, so that you can drive on the 6 vehicle sims just south of there.