水底トンネルの役割は何？
Each of the tunnels that run underneath the East and Hudson Rivers were marvels of engineering when first constructed. The Holland Tunnel is the oldest of the vehicular tunnels, opening to great fanfare in 1927 as the first mechanically ventilated underwater tunnel. The Queens Midtown Tunnel was opened in 1940 to relieve the congestion on the city's bridges. Each of its tubes were designed wider than the Holland Tunnel in order to accommodate the wider cars of the period. When the Brooklyn–Battery Tunnel opened in 1950, it was the longest continuous underwater vehicular tunnel in North America, a title it still holds. The Lincoln Tunnel has three tubes linking midtown Manhattan to New Jersey, a configuration that provides the flexibility to provide four lanes in one direction during rush hours, or three lanes in both direction.
0 to relieve the congestion on the city's bridges