Now Playing: Tour of the truck cabs these female truck drivers live in while on the road

Now Playing: Female trucker gives self-defense tips

Now Playing: How this female trucker deals with men on the road

Now Playing: Comey does not know why Trump is reluctant to call out Vladimir Putin

Now Playing: Comey weighs in on if he thinks Trump will be impeached

Now Playing: Comey on Trump tweeting about possible 'tapes'

Now Playing: Would Comey be a witness for Robert Mueller?

Now Playing: James Comey Part 3: Trump asks for 'honest loyalty'

Now Playing: James Comey Part 4: Discussing Michael Flynn

Now Playing: James Comey Part 1: Telling Trump about the 'dossier'

Now Playing: James Comey Part 2: The Hillary Clinton email investigation

Now Playing: James Comey Part 5: Are there Trump tapes?

Now Playing: James Comey Part 6: Comey on a Trump impeachment

Now Playing: Comey: 'It's possible' the Russians have something on President Trump

Now Playing: The moment Comey thinks Trump turned on him

Now Playing: Comey thinks Donald Trump is unfit to be president

Now Playing: Comey on comparing President Trump to a mob boss

Now Playing: Comey says he slept with a knife by his bed

Now Playing: Comey's wife warned him: 'Don't be the torture guy'

Now Playing: What Comey says he would tell Hillary Clinton today