CALIFORNIA:- California officials are warning of travel chaos over the weekend, as one of the largest land border crossings in the world closes for construction. The San Ysidro Port of Entry - between San Diego, California and Tijuana, Mexico - will close to southbound travellers for 57 hours. Pedestrian, tram, and bus crossings, as well as northbound car travel from Mexico, will not be affected. Tens of thousands of people pass through the border every day. The $741m (£546m) expansion project is expected to cause traffic delays until it is completed in 2019.