Construction lines are one of the ‘tells’ that indicates that a circle is potentially man-made. These lines are flattened first guide the circle makers, the best way to think of it is these lines are the outline of the circle. These lines tend to stand out on aerial photographs as being somehow brighter than other lines or areas that have been stomped. Consider the following circle…
If you look carefully, you will notice that there is the brighter construction line following the ‘arm’ of each section of this circle. This section of crop would have been laid first to guide the circle makers when making the rest of the circle. Now many will say that these lines are caused by people following the flow of the circle, but people walk all over crop circles, they don’t just follow the same lines as everyone else. If this was the case then these lines would appear everywhere. They are construction lines. Not every circle has obvious construction lines as many circle makers now try to design their formations so construction lines are not that vsisible, but you will be able to find them when you get to the field itself. It’s something to look out for…
Circular State of Mind 