What side of the road do they drive on in the Vatican?

I'm making a wiki about countries, politics, government, dependencies, etc., and one of the things I want to put for each country is what side of the road they drive on. However, neither Wikipedia or Google were able to ist me in finding out what side of the road they drive on in the Vatican City. If you could tell me, it would be much appreciated. Here is the article: http://nationalpedia.wikia.com/wiki/Vatican_City