Fiction: The First Sentence

I'd like some feedback on the first sentence of my novel-in-progress. First sentences are so, so, so important. I often open books in bookstores or the library, read the first sentence, and dismiss the whole thing or keep it based on that sentence. Even though I hate Hunter S. Thompson's content, he is a MASTER of first sentences.

I think in fiction it's important to start in medias res, so I usually try to picture the opening scene (fiction plays out like a movie in my process) and start it the way I think a film director would start it. In this case, I want a pick-up screeching around a corner dragging a toboggan behind it by a chain. Our heroine rides the toboggan.

Right now, it reads: The toboggan hit the packed ice on the asphalt faster than I thought it would.

As I'm staring at it, though, I'm wondering if it's clear that the asphalt is actually a road.

I wonder if that needs to be clearer in the first sentence.

• The toboggan hit the packed ice of the highway faster than I thought it would. -- Is that more interesting? Are you curious as to why the hell a sled is on a highway?

• My toboggan hit the packed ice of the highway faster than I thought it would. -- I think this might be better, because now it's clearer that the narrator is the owner of the toboggan. But is it clear she's riding it? What do you think?

I believe you need to get as much plot and mystery into that first sentence as possible. The reader HAS to want to know what happens next or you're already doomed. People have a tendency to give a bunch of backstory at the beginning. Don't. Save the backstory for later.

Of course, I have never published a novel, so I might be completely wrong. What do you guys think? How do you fiction writers approach the first sentence? What do the publishers, agents or editors think?

Rita Arens writes at Surrender Dorothy and BlogHer and is the editor of Sleep is for the Weak. She is BlogHer's assignment and syndication editor.