Tufts University has hired a consultant to review an intersection where a serious pedestrian accident occurred earlier this month, according to a university official. Tufts plans on making significant safety modifications to the intersection of Powderhouse Boulevard and Packard Avenue next spring, university spokeswoman Kim Thurler said. On Nov. 8, a 21-year-old Tufts student was critically injured when he was struck by a sport utility vehicle while crossing the intersection. The university said it has hired transportation engineering company Vanasse Hangen Brustlin to study the crossing and make safety recommendations. The company will begin a review of all roadways on the edge of the Tufts campus when that study is complete, Thurler said. New signs and improved lighting have been added to the intersection since the accident, according to a Somerville city spokesman.