Road markings can be confusing even for a confident driver as the shape, colour and location all affect their meaning. The Department of Transport's traffic signs manual explains why road markings are vital and play a role that upright road signs can't always fulfil. Road markings: How well do you understand the colours and lines on the road? (Image: Supplied)It reads: "Road markings serve a very important function in conveying to road users information and requirements which might not be possible using upright signs. Sam Sheehan, a Cinch motoring expert, said that not understanding zigzag road markings correctly could lead to a fine.