You can't spend a speck of time in Boston without hearing the term Big Dig. The "dig" is otherwise known as the Central Artery/Tunnel Project. It is responsible for the drills, elevated cranes, crews of workers, and other construction paraphenalia that blanketed downtown Boston for years. It was created as a way to solve Boston's legendary traffic problems. The city's downtown highway, the Central Artery, can't be expanded in place. There is no other place to put a new highway, so the only alternative was to build the new highway underneath the old one. Because the work took so long, there was no choice but to invest in the techniques that kept the city open for business during construction. Above the highway, city dwellers and visitors will find parks and green spaces. The open space has facilitated the connection of the isolated North End and Waterfront to the rest of the Downtown area.