The Massachusetts Department of Public Utilities order this week to the MBTA to cut speed on some rail lines is unprecedented in its scope, according to transit experts.The DPU, assigned by the federal government to watch over safety and reliability at the T, was criticized in a report last year by the Federal Transit Administration, which questioned the DPU's ability to perform real independent oversight.The slowdown order may be a sign that the DPU is ready for a bigger role, but it's still just a first step, according to Kate Dineen, the incoming president of A Better City."I think questions remain about the DPU's ability to effectively oversee the T, and I think it's really clear the DPU cannot do it alone, and they really need the partnership of a really strong board to oversee the MBTA," Dineen said. "And the DPU also needs the partnership of the FTA at the federal level."Dineen also praised T's open and transparent response to the orders — a marked change for the T, and that the DPU is adding more staff for oversight.An FTA spokesperson said the T informed it of the speed restrictions and that "FTA encourages the MBTA to commit to maintenance necessary to reduce the number of track defects on the system. FTA’s Safety Management Inspection report highlighted the number of track defects across the MBTA system."