BOSTON – Seventeen cents of every dollar spent by Boston residents goes to pay for transportation, according to a new study by the U.S. Census Bureau.The report, based on 2005-2006 survey results for household expenditures, shows the average Bostonian spent $9,170 on transportation, or 17 percent of the overall expenditures.By comparison, New Yorkers spent $7,792 and Philadelphia residents $7,092. The average throughout the Northeast was slightly higher than those two cities, at $7,776 but below Boston.Washington, D.C. residents paid the least amount for transportation – $7,341 or 12.6 percent. Houston residents paid the highest – $11,636 or 20.7 percent.Transportation expenditures include vehicle purchases, gasoline and motor oil, other vehicle-related expenses, and public transportation costs.The federal Census Bureau during October is collecting information about how much Americans spend for groceries, clothing, transportation, housing, healthcare and other items in an effort to keep the data current.According to Kathleen Ludgate, director of the Census Bureau’s regional office in Boston, about 7,000 households will be interviewed once every three months over five calendar quarters to obtain data on relatively large expenditures and also for those expenditures that occur on a regular basis, such as rent and utilities.During the year, the Census Bureau field representatives will also gather information from another 7,000 households who are keeping two consecutive one-week diaries of smaller, more frequent purchases – fast food from a drive-through window, soda or candy from a vending machine, a carton of eggs from the corner convenience store.The collected data provides a snapshot of the nation’s economy and spending habits, said Ludgate, noting that government economists use the results to update a “market basket” of goods and services for the Consumer Price Index, the nation’s mostly widely used measure of inflation.”Findings from this survey help business and community leaders make sound decisions,” she said. “Business owners get the information they need to help respond better to consumer needs, as do government officials planning public services.”Before interviews are conducted, households receive a letter from the Census Bureau, with notice they have been selected to participate in a government survey.