I hear some styles of barb wire can work... else it'll scratch the paint job and really piss them off

We have some drivers like that in our city.

Thank you for your sympathy and practical suggestions.

Now off to find some concertina...

Claymores work best.

Dress up like a homeless man and attack cars that are going the wrong way. After a couple rounds with the nutcase on Krupo Street, you'll see less cars doing it.

But a more serious suggestion is to petition the city council to put up a spike strip for anyone entering the road the wrong way. If it's a serious enough problem and they haven't used up thee budget by the end of the year there's a pretty good chance.

Another good idea. I don't think Toronto has ever had those installed though on a public street, so I'm afraid I ahve to wait for a fireball of carnage before anything happens. I really like both ideas, though.

"Face Side Towards Drivers"

Sniper Rifle