It's just a matter of style used... Some manage to create something like this in the most simple ways...
It's like when people create this overly über detailed looking model of a character, with shading and all... But in reality, it's just a mess of lines, and not carefully drawn lines as one would have thought, the style however, makes it look pretty much equally as detailed as those carefully-drawn-out lines...
So it's the same case here, it really doesn't have to be complex, as long as the style used (assuing you've developed one) does the job well... I think it's a matter of placement and angles and stuff, that makes these speed-lines look as complex as they do, simply because they fit so well where they were placed, but in itself, they are fairly simple to create...
So again, just an illusion, but it's not only how to draw them (like i assumed, only requires a certain style that fits) but mainly just hwere they are put, and how they are used...