What am I?

I'm a traveler who has been far and wide. I work hard and everyone depends on me. My day to day life wears me down, but I never give up. I'm usually dependable, but one cold icy winter day I was not. I failed on that fateful day. I lost faith in myself and the people who depend on me for support lost faith in me as well.  I have to start by saying that I hate the rain and the only thing worse than rain is ice. They make life difficult and they make my job twice as hard. I'm always on the front lines every time we leave home. I'm under a lot of pressure and that cold day when I was met with the challenge of that winter morn I lost my grip on everything. I lost all control and no matter which direction I turned it did me no good. I was out of control, and there is no way around that fact. I'm just glad that my failure to hold on didn't cost everyone their lives.