the man/woman/person in(on) the street

a typical, ordinary person

• Do the plans for celebrating the millennium take into account the views of the man in the street?
• Maybe the man on the street doesn't think this problem is very important.
• Her research looks at what the woman on the street thinks about the police.

...http://idioms.thefreedictionary.com/street

• The average man or woman in the street doesn't know very much about immune disorders.

... Cobuild, http://eedic.naver.com/eedic.naver?mode=word&id=27802&rd=s