[logpogingg]

Robert Frost once asked, "You see the snow-white through the white of frost?" Yes, Robert, we at the Fourth-Place Medal Investigative Unit do see the snow-white. Except there are also various shades of blue painted on it.
One of the most popular queries so far during the 2010 Winter Olympics has been about the blue lines that are painted on the downhill skiing course at Whistler. Try watching Lindsey Vonn race without wondering what they're for, why they're there and, most importantly, why the heck they're painted blue.
Because of our desire to impart Olympic-related knowledge upon those who seek it, the FPMIU today looks at the mystery of the blue lines on the ski slope:
The two vertical blue lines are intended to give skiers a clear path down the mountain. It's a safety issue. Much like with pre-schoolers and coloring books, there is no penalty for going outside the lines. However, downhill skiers can't stray too far outside because the guide is flush with the limited number of control gates that competitors must pass through. Staying in the middle isn't necessarily the best path.
There are also horizontal lines stretching across the course. Those exist to provide depth perception to the racers. Ever stepped into a snowbank that was a lot deeper than it looked? Now try going downhill at 90 mph and doing the same thing.
Numerous methods have been used in the past for safety reasons (the blue line is a relatively recent development in the long history of skiing), with pine needles serving as the most popular. Race officials often sprinkle the needles at the bottom of a jump so skiers know where the landing area is.
Lines are painted before the race by an official wearing a backpack spray tanker. Why blue? Because it pops and looks better than red. Source

[BalaGire]

Unaware it was a mystery. It really helps when the light is "flat". There were a few WC races this season w/ Fog and Heavy cloud cover that had more Blue lines than usual, and sometimes it still did not help w/ seeing the bumps on the course.