A transit system that truly serves Honolulu — which, after all, has tourism as its chief economic engine — needs to include the airport and Waikiki from the start.

So the news from Honolulu Hale on Friday was encouraging: Mayor Mufi Hannemann announced plans to include the airport spur in the initial buildout of the transit system.

And a public-private partnership is in development that will help connect tourists and Waikiki employees to their destination from the Ala Moana terminus, using enhancements to the city bus system and a private shuttle service.

The plan is still preliminary, and the financing plan will take state cooperation, but O'ahu commuter statistics support the basic concept:

• An estimated 7,000 people work at the airport, and those who live in Leeward O'ahu would be served by this change, sooner rather than later. Those who are airport-bound will either take the rail or drive to the Middle Street station and take the spur.

• About 58,000 people arrive and depart daily through the airport now, with those numbers only expected to rise over the coming decade. Their use of the transit system would help to sustain operations. From the airport, the ride to the end is expected to take 17 minutes — and take many vehicles off the road.

• The proposal will appeal to residents of urban and East O'ahu, who previously felt their tax dollars were supporting a project that didn't serve them. Now, with a park-ride facility at the Middle Street transfer station, they will have easier passage to and from the airport, something useful to virtually every O'ahu resident.

As it's redesigned, the spur goes from the Middle Street transit station to Honolulu International Airport rather than extending all the way to Pearl Harbor. Although the harbor extension should remain part of the full alignment, it makes sense to ensure that the airport comes on line as soon as possible.

The shorter airport spur saves about half of the original cost of $700 million. The mayor proposes that the $350 million add-on could be paid for if the city could reclaim at least a portion of the 10 percent of the transit tax that the state now charges for administering it.

That makes sense, particularly since the state now has the system in place for administering the transit tax within its existing framework.

It's the better funding mechanism than an alternative suggested: using part of the $480 million airport reserve fund. This money should be held for improvements of the airport facility itself. There is rationale to tap part of it for the construction of the terminus at the airport itself, but the transit tax, which was approved for the express purpose of building a transit system, should be the funding source for constructing most of the spur.

Financing this project is an issue the Legislature needs to address when it convenes for the 2009 session.

Providing a key transportation service to the tourist industry would benefit the entire state, so lawmakers should see the long-term benefit of this plan.

The second half of the proposal, to work with General Growth Partners on a shuttle service between its Ala Moana Center property and Waikiki, should be a win-win.

The developer, which would contract with a shuttle operator and provide depot space near Nordstrom, would not gain directly from tourist shuttle fares, which the contractor would set. But the company surely would see increased business from tourists making the circuit, and the city will get increased ridership from visitors wanting reliable transit to their hotels.

What's needed, and what the city administration pledges to provide, is enhancement of its bus service for Waikiki workers who also need transportation into the tourist hub. The plans for that — and for similar circulator buses to the University of Hawai'i-Manoa, should begin as soon as possible.

After all the rancorous debate on the plans for the transit system, it's encouraging to see practical solutions being conceived that will help to make Honolulu's multi-modal transportation system a reality.