The Big Dig's First Descent

"...officials are taking precautions, including lowering the speed limit and laying down a high-traction surface before this weekend's opening of the soutbound Interstate 93 tunnel....The grade for this stretch is 5 percent, meaning that the road drops 5 feet for every 100 feet traveled, the steepest decline allowed under federal highway standards. That drop, combined with drivers' unfamiliarity with the new highway and what may seem a sudden appearance of the tunnel entrance, has raised concern among project engineers."

Thanks to Connie Chung