According to the Microsoft website, Streets & Trips has been discontinued. Microsoft's mainstream support for Streets & Trips ended as of July 14, 2015. As of December 2015, Microsoft recommends using Bing maps as an alternative.
As of December 2015, Microsoft has discontinued support for its versions of Streets & Trips, suggesting that updates are not available for Streets & Trips 2012. In addition, an older link on the Microsoft website that does show a download for a construction data update for Microsoft Streets & Trips only provides a download for year 2011. There is nothing seen in the link related to updates for Streets and Trips 2012. The website with the download link was last reviewed as of May 23, 2012.