[belorn]

If we are talking about the actually root servers, there are 13 redundant names spread out (thanks to anycast) on around 1700 servers located around the world, and the lookup a user would do is cached for 2 days. That mean the highest amount of traffic a system will generate is one request per unique TLD (like .com) per 2 days, and it will fit a single UDP package.

We can then do some guesses about size for questions like "what is the nameservers for .com". Those are a bit larger than most dns queries since the answer is a bit bigger than most, since .com has a lot of nameservers, so lets put it down to 800 bytes. Every 2 day a average use might then, using some guessing, generate maybe 10 kb of traffic, or about 0.015 seconds of watching a 1080p video on youtube.