The tunnel acts as a major access to the northwest part of New Territories and mainland China from Hong Kong Island and the Kowloon Peninsula. It greatly eases the stress on the overloaded Tuen Mun Road brought by the rapid development of new town of , and , and the drastic growth of traffic on Lok Ma Chau access to mainland China.
Kowloon Motor Bus, and Long Win Bus operates bus routes that travel through the Tai Lam Tunnel. Discount is available to passengers travelling between designated bus routes.
* Kowloon Motor Bus: 68M, 68X, 69M, 69P, 69X, 251M, 263M, 264M, 265B, 265M, 265P, 268B, 268C, 269B, 269C, 269D, 269M, 279X, 373A, 968, N269, N368
* Citybus: 967, 967X, 969, 969A, 969B, 969P, 969X, N969
* Long Win Bus: A43, E34, E34P, E34S