Take this attempt from the article to quantify the economics.
Assuming a full-time job, $3 gas, 26 mpg and 50 cents a mile for maintenance and no parking fees, a 50-mile roundtrip commute costs $646.15 a month, or $7,753.80 a year, according to the City of Bellevue, Wash.'s, Commute Cost Calculator.
In my experience, this is way too high. Maybe, if you count the cost of buying a car and paying insurance on it you will be close, but many city dwellers have these costs too, even if they don't drive to work.
But, lets pretend for a little while that $0.50/mile is a realistic cost for maintanence. Lets also pretend this figure has not changed significantly over the last 5 years and won't change significantly over the next 5 years. At the hypothetical situation presented, the gas for the commute costs about $0.12/mile. This means that when gas went from $1.50/gal to $3/gal it only changed the cummute cost about $0.06/mile. The 50-mile roundtrip has only become $65/month more expensive in that time. The majority of the $646.15/month saving calculated in the article is the maintenance, which isn't affected by changing gas prices and therefore doesn't support the premise that rising gas prices could kill the suburbs.