I haven’t done any calculations but I agree that it doesn’t seem like an impossible transport job.
From the article it indicates the following:
....He has also spoken with UTIMCO, which owns the 6,643 gold bars housed underground in New York City.
He said the measure wouldn’t pose a significant expense, because the gold bars could be safeguarded in a small area, no bigger than 20 square feet.......
http://www.star-telegram.com/2013/03/21/4721036/tarrant-lawmaker-seeks-to-create.html#storylink=cpy
Something doesn't add up here.
From the U.S. Mint website, the standard gold bar weighs about 27.5 lbs.
6,643 of them would weigh 182,682 lbs. or 2,922,920 oz.
At ~$1600 an ounce, that amount of gold would be worth over $4.6 billion.