milk run

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A routine trip, usually involving stops at many places.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A routine trip, especially one involving several stops
• noun military (slang) An uneventful mission, especially a military sortie completed without incident
• noun politics (slang) A campaign for a political office whose main apparent purpose is to "milk" money from supporters in order to provide a source of income for the candidate, campaign staff, and family members.
• noun the picking up of mixed loads from multiple fixed sources on a regular routine like basis.