While small in size, the city’s proposed transitional centers could represent a game-changing advance in its approach to the homelessness crisis.

This week’s announced plan by the Caldwell administration to get new transitional shelters ready for operations by fall means more homeless individuals and families can be helped through the "Housing First" model of social-service outreach.

So far two locations have emerged for these transitional centers:

» A parcel in Waianae to accommodate no-frills modular units.

» A larger site, dubbed Hale Mauliola, on a state-owned lot of roughly 4 acres on Sand Island.

Both appear to be good pilot projects, but once the city can chart a course to success with them, expansions of this initiative should be considered.

The Sand Island location will use modified shipping containers that will accommodate up to 100 individuals at a time, but the city has proposed a two-month limit on how long people can stay in the transition center, so as to make way for new residents to gain access to the social-service support. There are many others now living on the streets who need a period of stability to regain their bearings and get on a more self-sufficient pathway.

The precise terms of residence will be tested in the pilot of this program and may need to be adjusted. But the basic concept is correct: This is not a place to put down roots, but a means to a desirable end. Officials would be wise to select the chronically homeless who show the motivation and capacity to gain from the services and move on.

A "safe zone" such as the Sand Island center enables the delivery of intensive interventions — help with substance abuse and health issues, and with preparing for rehousing and employment. That is the essence of Housing First: safety, security and basic human comforts from Day 1, then attention to other barriers the homeless struggle to overcome.

Honolulu officials also made a good choice to make the safe zone better than an alternative camping site of tents and few amenities. The city cannot compel people to relocate there, so the center must be appealing enough for families now roughing it on sidewalks, along canal banks, or wherever the encampments have sprung up.

On Tuesday the city issued two requests for proposals, one to construct the modular container homes and one to provide supportive services on site.

Bids are due June 19 for services providers and June 24 for the builders, and the city will need to hew closely to that schedule to make the deadline.

Some other elements:

» The site will feature 24-hour security and staffing.

» A contractor will remove the kiawe and the city will grade the site. The soil recently was tested and deemed safe by the state Department of Health, but the city also will apply a smooth, recycled asphalt surface.

» Each of the 25 containers will be subdivided into three or four units that will have windows, a lockable door and portable lighting. Pets that don’t threaten other residents will be allowed.

» A central hygiene trailer with private individual showers, toilets, sinks and electric outlets will be provided, as well as washbasins and clotheslines. There will also be a common area for residents and a meal service.

» Shuttles will be provided to the nearest TheBus stop.

» Social service staff will work from an intake center and program office.

Initial construction will cost $500,000, with annual costs of about $1.5 million for support services at Hale Mauliola.

At around the same time this fall, city officials said, they expect to open a project with three modular units on a 7,500 square-foot Halona Road in Waianae — a test site the administration intends to expand.

The city needs to continue outreach to the neighbors, who have concerns about how the project could affect their own properties.

A presentation planned for next month before the Waianae Neighborhood Board should provide the details on security and project design that area residents need to hear before families move in.

Once such provisions are in place, however, it’s time for Oahu residents to step up and find a place for these centers. The homeless ultimately should be rehoused at various locations scattered throughout island communities, but these way stations are desperately needed as part of that process — and as soon as possible.