Fitbit and Commuting

I know I should ask this on the Fitbit board, but I like MFP people too.

With your Fitbit experience how do you find long commute time effects the reading?

Currently I drive 30 miles to and from work every day, and it takes me about an hour. I may be getting a job where I'll temporarily be commuting by commuter train an hour and a half each way (3hrs total). I have the Fitbit One.

Does anyone do a lot of land travel and do you think it messes with the accelerometer or not too much?

This is more of a curiosity thing, but I know that when I do remember to wear my Fitbit I try harder to make my step count and I like the baseline for my BMR and the "guesstimation" of the calories I've burned for the day.