Construction at stations in Plano and Richardson is expected to begin March 25.

Construction projects will affect passenger light-rail stations in Plano and Richardson beginning March 25.Dallas Area Rapid Transit said commuters who use the downtown Plano and Galatyn Park stations should use caution during the four-month construction projects. The transit agency also said riders should allow extra time for connections at bus and light rail stations.The construction will expand capacity at both stations, and 28 other Red- and Blue-Line stations are slated to undergo the same construction in the next two years, according to a company press release.Meanwhile, work on the 26-mile, east-west running Cotton Belt line is expected to begin sometime this year. The Cotton Belt will add two new stations in southeast Plano at 12th Street and Shiloh Road as well as stations in Richardson at the University of Texas at Dallas and the CityLine development.The DART board of directors unanimously approved the addition of a second track along the future Cotton Belt line in February.