SAN DIEGO–A scheduled closure of the region’s coastal rail line will be in effect this weekend to allow SANDAG crews to work on rail improvements, test signal equipment, and connect new railroad tracks near the San Elijo Lagoon.The rail closure affects four railroads operating on the San Diego segment of the Los Angeles-San Diego-San Luis Obispo coastal rail corridor: North County Transit District, Metrolink, Amtrak, and the freight carrier BNSF. SANDAG is double-tracking much of the rail corridor to improve capacity for all four operators. In addition, SANDAG is preparing for the installation of the separate set of tracks for the under-construction Mid-Coast Trolley, which extends the Blue Line Trolley from Downtown San Diego to University City. The planned rail closure, called an Absolute Work Window in rail parlance, will take effect just after midnight on Saturday, September 8 and continue through 5 a.m. on Monday, September 10. Regular passenger rail service is scheduled to resume in time for the morning commute on Monday. Riders are encouraged to allow for more travel time on Monday, as trains could be delayed in arriving at their destination. In Cardiff-by-the-Sea, construction crews will connect the newly installed second rail line to the existing track and trains will begin running on the new track Monday. This is part of a $72.8 million project to add 1.5 miles of double track from Cardiff-by-the-Sea to the southern border of the San Elijo Lagoon. The project also includes a new bridge over the lagoon and a pedestrian undercrossing at the southern end of the lagoon. The San Elijo Lagoon Double Track Project is expected to be complete in 2019. Construction crews also will conduct vehicle flagging operations for intermittent lane closures along San Elijo Avenue in Cardiff-by-the-Sea for the Encinitas segment of the Coastal Rail Trail. The project will provide a 1.3-mile walking and biking path along the east side of the railroad tracks near San Elijo Avenue, from Chesterfield Drive to the Santa Fe Drive undercrossing. The Encinitas segment of the Coastal Rail Trail is expected to be complete in 2019. In Bay Ho, crews working on the Elvira to Morena Double Track project just east of Interstate 5 will build walls and bridge structures, and work on the tracks within and near the railroad right-of-way along Santa Fe Street and Morena Boulevard. This is being done in conjunction with Mid-Coast Trolley Project. The $192 million Elvira to Morena Double Track Project will add 2.6 miles of second main track. Once complete, it will result in 10.3 miles of continuous double track in the area. In Linda Vista, on the rail bridge over the San Diego River, crews will remove temporary structures and conduct tests along the bridgework of the $93 million heavy rail project. A new light rail bridge for the Mid-Coast Trolley will be built parallel to the bridge. The heavy rail San Diego River Bridge project is expected to be complete in 2019. For a schedule of alternate routes for passenger train service, visit GoNCTD.com, Amtrak.com, or MetrolinkTrains.com.