Smiling makes me feel like I look crazy, but I'm just smiling

I tried smiling while driving today. Not for any particular reason, just that it seemed better than frowning.

I've heard that it takes less muscles to smile than to frown, and even though I may not be smiling most of the time, I'm not frowning either. I usually find myself with my facial muscles relaxed because there is no effort in it. My expression is probably not interpreted favorably, though. I'd say I look angry, or empty, or unapproachable. Really I'm just focused, and maybe a little anxious. Just doing what I do, while going where I'm going.
I should smile more. Imagine, you're driving down the road and you slow to a stop beside me at a red light. You look over at me, and I'm just smilin' away. My windows are down, there's no radio coming from inside my car, it's hot as (insert expletive here), and I'm just grinnin' away. My cheeks are pushed up under my eyes and I'm squinting, but I'm definitely smiling. I probably look crazy, but I'm just smiling.