Pretty impressive work being done at this construction site. I love the "machine" they are using for coating the inside of the tunnel with concrete. It's a giant steel and hydraulic monster that crawls through the tunnel while applying the 6" or so thick reinforced inner shell.
Maybe their contract was for a certain length and they underestimated. Maybe they want to keep the entrance and exit separated so that late night drunk drivers do not accidentally enter the wrong tunnel. Maybe they want a place to install advertising billboards.