Although the Senate did its part in approving a $60 billion transportation-funding bill, it may hit a traffic jam at the White House. The cause of the congestion is a provision calling for tougher safety requirements for Mexican trucks entering the U.S.

Both the House and Senate versions of the bill call for restrictions to how far Mexican trucks can travel within the U.S. Proponents of this measure say the Mexican trucks are not as tightly regulated as are U.S. trucks and therefore pose a safety risk on U.S. highways.

President Bush is threatening to veto the bill over the restrictions. It is Bush's plan to allow Mexican trucks widespread access to U.S. highways beginning in 2002. The New York Times reported Sen. Trent Lott (R-Miss.) saying he would find the votes necessary to support such a veto.