it's been done in america, including the blow up dolls that you can get also for 'security purposes', so it'll be there next. you yank lovers.
i think that it's a good idea. most of the traffic on the roads is full size cars with just one person in them. what a waste. why not have a bike or a small car?
you should be encouraged to share your cars more. over here we have parking places by motorway junctions so that people can car share on the motorways.
you never know, you might pick up a well fit nympho bird who can't keep her hands off you. that might backfire though - the camera to pick up passengers wouldn't see her if she went down on you for a bj
seriously though, it really shouldn't be necessary if you had proper lane discipline. over here, a lot of the motorways are good old adolf's original's from the war and are only 2 lanes. trucks are not allowed to overtake (they're all limited to the same speed anyway, so where's the problem?) and people move over when they've finished overtaking and look before pulling out, otherwise they risk having an s class ram them up the arse at 155mph.
if it is introduced, maybe you'll be able to hire illegal immigrants to be your passenger for the day? got to be safer than going cockling?