Mercer Island has relatively high levels of vehicle ownership and personal mobility. Approximately 70 percent of the households on Mercer Island have two or more vehicles, while less than five percent of households have no vehicle at all. Comparing the 2016 American Community Survey (US Census) data with the 2000 US Census data, a number of changes are observed.
The percent of Mercer Island residents who commute to work by driving alone has dropped from 76 percent to 72 percent, those who take a bus or carpool to work decreased from 17 percent to 14 percent, and those who work at home increased from 7 percent to 10 percent. The average travel time to work for Mercer Island residents is 25 minutes, which is below the regional average of 32 minutes.
A November 2013 WSDOT Mercer Island Travel Survey found that 55 percent of commute trips originating on the Island traveled west towards Seattle and 45 percent traveled east towards Bellevue.