The rail project provides transportation, of course, but also a chance for transit-oriented development (TOD) at each of the 21 planned rail stations. The time has come to make the most of that chance.

The Honolulu City Council Zoning and Planning Committee has advanced Bill 74, the legislation introduced in 2015 to lay the ground rules for development within the quarter-mile to half-mile zone around the stations.

There needs to be a refinement in the bill before its final passage, spelling out more clearly the expectation for developers, especially regarding affordable housing.

The promise that the rail system can enable more desirable conditions for development — offsetting some of the usual burden of land and utility costs, for example — has been part of the argument for the projects.

Indeed the east-west alignment of the 20-mile rail connects established communities, some of which could greatly benefit from new commercial and public services.

Two of these are the ones near the front of the line, the West Loch and Waipahu stations. They are older communities, but positioned for more economic activity, given the robust growth in neighboring Ewa and Kapolei.

Developers provide community benefits in return for height and density allowances. These benefits could include various give-backs, including public open space as well as affordable housing. The most pressing part of the equation, though, and the core of the city’s responsibility to the public, is closing some of the gaping shortfall in housing.

Developers, and some Council members, rightly argue that affordable housing at a range of price points is in demand, but certainly the lack of affordable rentals for those at the lowest end of the income scale is the most critical need.

One proposal would require that any project with 10 or more dwelling or lodging units would need to set aside 30 percent as affordable. Those units would be priced for households not exceeding 120 percent of area median income (AMI), with two-thirds for those at 80-100 percent of AMI. However, even that language was not included in the bill the committee moved.

Among the newly ratified amendments to the City Charter is a provision to establish a land management agency within the city administration, one that would pull together city personnel and resources devoted to the oversight and streamlining of development processes.

That agency, which has been touted as a means of fulfilling the promise of TOD efficiently, must be created with rules ensuring proper public engagement in the process, rather than cutting corners on transparency.

Further, this agency must not have the power to circumvent the guidelines on TOD; the Council’s ordinances are the paramount rules there, which is why they must be written with such care.

Some projects already in the pipeline show both the potential and pitfalls of TOD. When complete, the Halekauwila rail stop will include a vibrant mix of affordable rentals, workforce housing and retail, as well as a “vertical school” in one of the projects.

But, another project near the Ala Moana Center terminus moved through the process without affordable housing provisions on-site. The city can’t afford to miss many residential opportunities in fulfilling its TOD mission.

Faith Action for Community Equity (FACE) and other advocacy groups are pressing the city to raise the bar and ensure more units for low-income renters. Catherine Graham of the FACE Housing Task Force cited an estimate placing the affordable-housing deficit at 64,000 units and called on stakeholders to work cooperatively on the mission for the next decade.

”All of us need to participate in making this dream a reality,” she said. That effort starts with strengthening Bill 74.