HONOLULU (HawaiiNewsNow) - Rail transit may be the largest-ever public works project. But all that private development along the rail line is going to be even larger. A lot larger. "While rail is going to be a $5.2 billion construction project, TOD over the decades ... could generate $20 billion worth of projects," said Mayor Kirk Caldwell. Caldwell cited a recent report by local economist Paul Brewbaker, who looked at the potential economic impact of the proposed developments along the 23-mile transit line. Based on those estimates, transit-oriented development, or TOD, would be the largest construction boom since statehood, exceeding the $18 billion Japanese investment bubble of the late 1980s and 1990s. But Caldwell cautions that all of that development won't happen overnight but could take 20 to 30 years. He said the city's task is to help plan each of those projects wisely, avoiding the planning debacles of past building booms. Fewer cars, more bike lanes and open spaces and plenty of new retail are just some of the ideas that they city wants to incorporate in its transit oriented development plan. "For us, the largest chunk of the $20 billion is going to be building affordable housing," Caldwell said. More than 100 people were at Washington Middle School Wednesday night to attend the city's TOD presentation for the rail system's final and busiest stop, the Ala Moana Center station on Kona Street. Many like Manoa resident Richard Fassler came away impressed. "I am very positive on this. I have been to a number of cities like Portland and San Francisco recently and have seen amazing things with what they have done with rail.," Fassler said. But others were skeptical. "Absolutely, there's too much development and they haven't proven to me what the benefits are," said Kakaako resident Marilyn Yeager. "We build expensive housing for people to come here and live. What are we doing for old people like me who are almost indigent."