Peterson rides his bike seven miles to his job at Fermilab in
In 2002, he built his tow-behind snow plow.
David Peterson posts the history and detailed construction plans for the bicycle snow plow at his website. I have no idea if he still uses this (the website was last updated in 2005), but I've sent Peterson an email and we'll see what he says.
Here's another bicycle snow plow photo I found randomly on the web.