REVERE-Middle school students are crossing busy Bell Circle on their way to Rumney Marsh Academy, raising safety concerns for school officials.”That may be a problem,” said Superintendent Paul Dakin, adding that school officials may ask the state Highway Department to consider placing a “caution pedestrian crossing” or traffic signal to improve safety during school hours.Rumney, the city’s newest middle school, opened Aug. 26 and Dakin’s worries about traffic backing up on American Legion Highway did not materialize.School traffic is an ongoing problem of varying severity around the city. West Revere residents experienced their share of it in 2006 while parking problems involving the opening of the Anthony Middle School and Whelan School that year were ironed out.Initial fears about Rumney’s traffic centered on speeding and potentially heavy traffic generated by drivers traveling to the adjacent high school and the new middle school.Complaints by residents living near the high school prompted councilors last year to ask police to step up patrols on four streets, including two near Revere High School, to counter speeding, heavy truck traffic and commuters using neighborhood roads as detours.They asked police to watch out for speeders on Carey Avenue and Mountain Avenue East after residents complained to Councilor at Large John Correggio about students speeding near the high school.Councilor John Powers raised a similar concern about morning rush hour traffic cutting through John and Mills avenues to avoid Route 1A. Powers said the shortcuts pose a danger to children boarding school buses on those streets.