We love Hawai'i. We want to live, work, play and raise our families in the Islands. We want our children to raise their families here.

But we also are contributing to the very development pressures we bemoan. Think about the first member of your family to step off a boat or a plane here; maybe it was your great-great grandfather. His growing family accounted for a single household. But he had children and they had children. Two, three, or four generations later, how many households of his descendants — your entire family — now live in Hawai'i?

And more people are arriving daily. O'ahu is the third-largest of the islands in land area, but three-fourths of the state's people call it home.

With a population density 10 times that of No. 2, Maui County, the City and County of Honolulu faces unique challenges as we strive to accommodate a growing local population, protect the environment and improve our quality of life.

There have always been people who greet development proposals with a "not in my backyard" refrain. Recently, the tune smacks more of "pull up the drawbridge, I'm here." People who indulge that conceit sometimes forget that someone might have once opposed the homes they now live in.

O'ahu's population will keep growing because we want our families to stay here, and development opportunities will continue to arise. We can manage this carefully by requiring developers to work with the community, be responsible citizens and contribute their fair share for the betterment of those areas they're affecting.

We must preserve open space and fulfill our obligations as stewards of the land, while accommodating growth. A good example is the city's work with the community to acquire Waimea Valley and protect it from development.

Whether we're building new subdivisions on former agriculture land in central and leeward O'ahu or redeveloping existing sites in the urban core, we must ensure the roads, sewers, water systems and utilities adequately serve these developments.

That might seem like a mundane task, but it's a vital one. If left undone, it can threaten public health and safety, as we witnessed in Waikiki in March. We're battling to catch up after years of neglect of our basic infrastructure on O'ahu, while the population continues to grow, placing it under more strain. And we're putting into place a philosophy and safeguards to ensure that future city administrations will have to comply, for the public will demand no less.

The populations of central and leeward O'ahu are booming, just as city planners and policy makers decided many years ago. Yet the transportation system has not kept pace.

Already thousands of central and leeward residents routinely spend an hour or more in traffic each morning to get to school and or work, and about the same getting home each evening. A study last year predicted commuting times would double in 25 years without major changes in our transportation system. That didn't include catastrophic disruptions like the one we had on Tuesday, which affected hundreds of thousands of people.

We will never be rid of automobiles, but we must provide alternatives to having people spend four hours a day in traffic. That's why we embarked on a campaign to build a mass-transit system. I've made no secret of my belief that a rail system offers the best prospects for an enhanced quality of life that would positively affect the environment and encourage smart growth and development.

A rail system would be part of a multimodal approach to offer people transportation choices. We are working on the commuter ferry between Kalaeloa and downtown Honolulu, which we hope to start next year. We're also developing more jobs in central and west Oahu; improving our bus system and bikeways and doing a better job of synchronizing traffic signals.

These actions are important. But building a rail transit system is the key because it appears to be the most cost-effective way to move large numbers of people in the years to come.

The rail system we envision would begin in Kapolei and head through downtown Honolulu to the University of Hawai'i. I asked our engineers and planners to devise a system that will cost around $3 billion in government funds — a basic, no-frills segment along that corridor that would move the most people with the most efficient use of capital funds.

We expect private money will also be available from landowners and developers at points along the rail line and we will seek public-private partnerships. Rail transit holds great potential for transit-oriented development, self-contained communities built around transit stations where people could live, work, shop and play without being so dependent on cars.

A rail system operating on electricity generated by ethanol (as Hawaiian Electric Co. plans for its Campbell Industrial Park plant) or some other alternate fuel would go a long way toward weaning Hawai'i away from petroleum.

And it's far easier to monitor emissions from a single electric plant than from thousands of automobiles, trucks and SUVs in varying states of repair. That has to be good for the environment. And as former Vice President Al Gore states in the movie, "An Inconvenient Truth," riding rail mass transit helps fight global warming.

Managing growth is a daunting challenge that we can meet with responsible, committed leadership for our O'ahu home.

Mufi Hannemann is mayor of Honolulu. He wrote this commentary for The Advertiser.