I had a $400/mo gas bill. 37 miles' commute each way, in an SUV I got for cheap (just 10k, 87k miles on it, perfect condition). But it's not like I could just simply move, and this was the first job I got that paid more than $8/hr. So I kept at it for a few years.
Point is, that's not an entirely unrealistic figure. And while it's not something one should be doing, a lot still are doing so because it really is the only option they have commuting from suburbia to the city. (ESPECIALLY living in a county that has a history of being anti-public transit, like Cobb and Cherokee in Georgia)