In the link below is a notice of coming construction on 11th, 12th, and Milwaukie. Transportation officials strongly suggests anyone using 11th and 12th between Powell and Division during January look for alternate routes, especially during rush hours. There will be lane closures, but at all times, at least one lane should be open. There are no plans, at this time, to close the roads completely.
This linked flier gives you more detail.