The Massachusetts Department of Transportation (MassDOT) yesterday launched an online performance dashboard for the Massachusetts Bay Transportation Authority(MBTA). The public can use the dashboard to track the daily reliability levels of the agency’s four subway lines and all 170 bus routes, MassDOT officials said in a blog post. The launch marks the first time that performance data for all four branches of the Green Line light-rail route is publicly available.  The dashboard reflects the same information used internally by the MBTA to improve the transit system’s on-time performance. It focuses on four categories: reliability, ridership, financials and customer satisfaction.