As former state transportation directors and a former deputy director for environmental health, we are intimately familiar with O'ahu's transportation needs and the importance of protecting our environment. That's why we are fully confident in our unequivocal support for Honolulu's rail mass-transit project.

Since the federal mass-transit program was initiated in 1964, cities and metropolitan areas in the U.S. have studied urban mass-transit systems to fix the overloaded highway systems used by cars, trucks and buses. Honolulu was no exception.

Under several mayors and governors, City Councils and state Legislatures, several independent studies have been conducted, each time concluding that some form of mass transit was needed.

Controversy and indecision prevented a decision every time. Today, everyone agrees that the system is broken, and needs to be fixed. Our highways are bumper-to-bumper with cars, trucks, and buses every day, for hours at a time.

Honolulu has a difficult geographic problem that exacerbates our transportation problem. The downtown business and government center is located in a narrow constricted "throat" between Punchbowl and the waterfront. Unlike other cities, we cannot build a circumferential or bypass highway to alleviate downtown traffic. It is obvious that putting more highway lanes through this constricted corridor is costly and foolish. The object is to move more people, not more cars and buses.

A light-rail system can carry several times the number of passengers per track (or lane) per hour compared to a bus system, and is clearly a more efficient and effective use of precious space through the expensive downtown corridor.

Many other cities have reached the same conclusion, that the best transportation solution for them is a combination of cars and buses on highways plus a high-capacity rail transit system, rather than an expanded highway system to accommodate more buses and cars. More buses are not the answer, because they will merely become trapped in the same gridlock as everyone else.

If they were to use new dedicated lanes like the light rail trains, they will be less efficient, more costly to operate, and produce more air pollution.

Rail is tested and trusted in cities across the United States and in countries throughout the world. Rail is a modern, reliable, convenient and environmentally friendly alternative to clogged freeways and expensive fossil fuels that pollute our air.

To remove light-rail transit from further consideration as advocated by the opponents in the petition being circulated is to ignore not only the exhaustive studies done by expert consultants hired by the city, but the accumulated evidence from other American cities of medium to large size that have opted for rail transit.

Building rail transit systems has long been viewed by health experts as an excellent way to limit harmful vehicle emissions and improve air quality. With mounting concerns about the link between greenhouse gases and global warming, rail makes more sense now than ever.

The draft environmental impact statement for this project is now nearly complete and will be distributed for public comment in the fall. Every aspect of this project is subject to the strict oversight of the Federal Transit Administration, which has offered major support for similar projects that were sidetracked in the past.

O'ahu needs a balanced transportation system, and the rail system will provide the backbone for a comprehensive multi-modal network that also includes buses, ferries, bicycle lanes, car pools, taxis and, of course, private vehicles. We've needed rail transit for decades, and rail technology has continued to improve. A steel-wheel-on-steel-rail system will be the most reliable, economical and efficient alternative.

The opponents of rail transit have a right to express their views and attempt to derail this project. But let's be very clear: There is no need for more studies and more delays. We commend Mayor Mufi Hannemann for his strong leadership on this issue. Rail transit has already been studied to death on O'ahu, and it is clearly our best transportation option. It's time to move forward. Far too much time has been wasted already.

Fujio Matsuda, Ed Hirata, Kazu Hayashida and Rod Haraga are former state transportation directors. James Kumagai was a deputy state health director. They wrote this commentary for The Advertiser.