By Keith Laing - 09/11/12 03:47 PM EDT
The MAP-21 bill includes about $53 billion for road and transit projects through the end of the 2014 fiscal year. Boxer's letter comes as the 2013 fiscal year is set to begin after Sept. 30.
Prior to the approval of the MAP-21 bill, the House passed a pair of extensions of the previous transportation funding bill that would carry road and transit funding through the end of fiscal 2012.
The Senate approved an extension of the previous funding through the end of June, and both chambers passed a week-long extension to allow the MAP-21 bill to be finalized in early July.