Treacherous railings in Big Dig tunnels
Specialists say that during an accident, arms and heads can too easily slip between the widely spaced posts in the safety railing fastened to the top of Jersey barriers, and that the barriers are too low to keep victims away from the posts.
SOURCES: Massachusetts State Police Collision Reconstruction reports; Central Artery/Tunnel Project; Dean Sicking, Midwest Roadside Safety Facility at the University of Nebraska-Lincoln
David Butler/Globe Staff

