If the quick is the enemy of the careful, why is Honolulu Mayor Mufi Hannemann in such a rush to build a mass transit system linking West O'ahu with the island's urban core at an anticipated cost of $5 billion or more? The mayor has repeatedly stressed that speed is a top priority. "Bottom line," he recently said, "we want this project to move along quickly."

A more fundamental question is what the citizens and politicians of O'ahu can learn from previous mega-projects undertaken here and elsewhere. The truth will not be comforting to the go-fast crowd, for the mega-project track record provides serious cause for concern that the biggest construction project in Hawai'i history may well turn out to be an unhealthy cocktail of underestimated costs, overestimated revenues, undervalued environmental impacts and overvalued economic benefits.

Consider two large construction projects in the state's recent history. Former Mayor Jeremy Harris' grandest attempt at civic improvement may be the huge Central O'ahu Regional Park, the crown jewel of which is a 20-court tennis complex for which the final price will be, according to the city's own auditor, at least $2.5 million more than the original $9.5 million contract and perhaps $5 to $6 million more than the initial $7.5 million estimate.

In order to make the tennis courts a reality, city officials inappropriately transferred money from other projects, violated internal financial policies and failed to provide records that would justify the expenditure of more than $2.2 million. Only four years after the courts opened, net posts are bending and rusting, gates open in the wrong direction, shower trees dump debris on the courts, and landscaping is poorly maintained.

But the largest and most expensive public works project in Hawai'i history is H-3, the highway linking Pearl Harbor to Kane'ohe. According to the U.S. Department of Transportation, H-3 was originally envisioned as a six-lane road through Moanalua Valley that would cost $250 million. By the time the highway through Halawa Valley was finished, the bill was $1.3 billion — a 500 percent expansion.

The problem could be illustrated with other projects — the new University of Hawai'i John A. Burns School of Medicine, Aloha Stadium, the Hawai'i Convention Center — that morphed into facilities with cost-benefit outcomes that hardly resemble what their original promoters promised. But the cautionary tales are not merely local.

All around the world one encounters multibillion-dollar mega-infrastructure projects. Boston has its "Big Dig," France and the United Kingdom have the English Channel tunnel, Germany has the MAGLEV train, Japan has the Akashi bridge, Hong Kong has the Chek Lap Kok airport, and China has Three Gorges dam, just to name a few. These projects are part of the human effort to create a social order in which individuals and their goods, information and money can move with minimum friction. Sometimes the ambitions are laudable.

But the problem and the paradox is that while more and more huge projects are being built, many turn out to have strikingly poor performance records. Bent Flybjerg, a Danish professor of urban planning and the head of a research team that has conducted the most comprehensive research on mega-projects and their risks, concludes that, in all too many cases, huge infrastructure projects involve: (1) calamitous cost overruns; (2) overlooked and ignored environmental problems; (3) exaggerated development effects; (4) misleading cost-benefit calculations; and (5) the violation of established practices of good governance, transparency and public participation in decision-making.

That's quite a list. The central problem is the risk-negligence and lack of accountability induced by project promoters whose main ambition is to build projects for private gain — economic or political — not to operate them for the public interest.

The planning for O'ahu's mass transit system is at a critical juncture. After a decision is made later this month about what firm the city will hire as its general engineering consultant, expenditures and momentum will accelerate rapidly. Details of those contract negotiations, as in many other mega-project plans, remain confidential.

But we do know a few things. The projected cost of this mass transit project has already risen from $1 billion in 1982 to $5 billion or more at present. The dismal track record of other mega-projects suggests that when O'ahu's system is finished — if it is finished at all — we should not be surprised if the end cost is double or triple the current projection, and with fewer economic benefits to the public and more damage to the environment than project promoters would like us to believe.

It would be wonderful if a mass-transit system could relieve some of the traffic congestion that frustrates so many residents of this island. But let's not be ostriches. Local, national and international experience with projects of this kind speak pretty clearly: Mega-projects are frequently not driven by concern for "the public interest." That's all the more reason for the public to get more interested.

David T. Johnson is an associate professor of sociology at the University of Hawai'i-Manoa. He wrote this commentary for The Advertiser.