Macroeconomics Question ?

There may be 20,000 parking spaces, but your paragraph erts that nobody will spend more than ten seconds looking for a parking space. If so, then the number of parking spaces that meet the criteria "found with ten seconds" is a lot less than 19,000. The definition of a scarce resource is something that is not available in unlimited supply. There are not an unlimited number of parking spaces downtown. -- and certainly not discoverable with ten seconds.