The Downtown Streetcar Working Group estimates a downtown streetcar system could cost between $42 million and $179 million, depending on length and amenities, and operations could be financed by taxes or surcharges on parking, hotel rooms and/or restaurant meals.  Capital costs would be funded from federal, state and local sources.  The working group, consisting of 42 community leaders, has developed three basic routes — Blue, Red and Green — that could be mixed to create seven lines.  The Blue Line would run approximately north-south along High Street from a loop at Frankfort Street north to Buttles Avenue.  The Red Line would extend the Blue Line to either 11th Avenue or 17th Avenue, with the latter circling through the Ohio State University campus.  The Green Line would loop through the area west of High Street connecting the Arena District, a portion of downtown and Grant Medical Center.  Annual operating costs would range from $4.6 million to $5.7 million.  “Theoretically, the working group could say we like them all or we want a combination of the Red and Green lines,” Dennis McGinn, chairman of the working group, told The Columbus Dispatch.  “On the other hand, it could be something more modest.”  Final recommendations are expected to be released this fall.