The Massachusetts Board of Elementary and Secondary Education approved four new charter schools for Boston, Holyoke, Lowell, and Springfield as part of a broad effort to expand educational opportunities for students in urban areas. The Holyoke, Lowell, and Springfield schools will operate independently of their city’s school systems and will open this fall or next fall. The one in Boston - the Dudley Street Neighborhood Charter School - will be overseen by the Boston Public Schools in partnership with two nonprofits.