There is one thing Honolulu's mayoral candidates agree on: the need for a multi-billion-dollar mass-transit system along O'ahu's traffic-congested east-west corridor.

And in these tough economic times ensuring that money is spent wisely is crucial.

But the EzWay system proposed by Councilwoman Ann Kobayashi — a $2.5 billion patchwork plan that includes an elevated guideway for cars and buses — simply doesn't make the grade.

It doesn't help that Kobayashi and her infrastructure adviser, Panos Prevedouros, introduced EzWay to the public only three weeks before the election. Kobayashi gave voters very little time to make a considered judgment about her plan as an option to rail — in itself a good reason for caution.

In contrast, the city's rail transit plan has been more than three years in the making — with numerous venues for public and City Council review along the way. It has been successfully vetted through the complex local, state and federal regulatory processes required to responsibly advance a public works project of this size.

The EzWay plan lacks a detailed, independent analysis, particularly from state, local and federal transit experts.

And on the fundamental issues — cost, funding sources, effectiveness — EZWay raises more questions than answers.

Here are a few things to consider:

• Cost: EzWay proponents say their plan saves money and that some components could be started almost immediately.

The entire project will likely require a new environmental impact statement, which typically takes years. The federal government will require a comprehensive review before issuing a dime.

Elevated highways for cars and buses are generally bigger, wider and more costly per mile than narrower fixed-rail guideways. EzWay's centerpiece is a three-lane, 15-mile elevated roadway. While shorter than the initial 20-mile rail route, available cost estimates on similar projects suggest it could cost far more than advertised.

Prevedouros suggests that construction could begin almost immediately by resurrecting the state's plan for the Nimitz flyover, a two-lane, approximately 2-mile elevated roadway that's along EzWay's planned corridor. But state transportation officials say the original environmental impact statement will have to be reviewed. Even so, the cost estimate in 2006 for the flyover was $225-$250 million per mile, which if applied to EzWay would significantly increase its price tag to the neighborhood of more than $3 billion. That doesn't include the rest of the EzWay plan, which has bus rapid transit connectors and road upgrades, a $75 million underpass near Alakea and Halekauwila streets, and expensive new buses.

• Funding: EzWay's hybrid highway/fixed guideway plan poses serious questions about eligibility for federal funds. Despite claims that EzWay would be eligible for both transit and highway funds, it's quite possible it won't qualify for either.

A 2006 opinion from the state attorney general made clear that the current excise tax set-asides for transit can't be used for "new public roads or highways." Without the certainty of a local funding source, qualifying for federal dollars will be all but impossible.

The rail transit project is much further along the right track; about $35 million has been cleared for use and the draft EIS is under federal review and due shortly. The project is expected to garner roughly $900 million in federal funding.

All four members of Hawai'i's congressional delegation support the city's rail project and have promised to aggressively seek federal funding should voters approve the plan. EzWay has no such support, which is critical for the future success of such a large and expensive project.

• Effectiveness: Will EzWay be more effective in reducing highway congestion than rail? The best available study of the question, the city's detailed, $10 million Alternatives Analysis, says no. It found that trains can move more people more efficiently than buses. Rail uses electric vehicles, which are more environmentally friendly than cars or buses, even fuel-efficient ones.

The choice is clear: Rail transit is by far the more prudent and effective plan. As part of a multi-modal system that includes cars and buses, rail offers the best long-term solution to O'ahu's critical transit needs. On Nov. 4, voters should choose Yes on Ballot Question 4 in support of rail transit.