Open the building bar at the bottom of the screen (the grey thing). Click on the road. The building bar will disappear, and a black selector box will follow your mouse. Click on green to place (clone) a road. So far this seems to work fine, but when you repeat this processes, the previous road clone goes over to the new one. If you know how to stop this, please give me a comment!
Press 'See inside' and look at the bottom of the 'Road' sprite at the comment.