The bulk of the city’s transit-oriented development (TOD) in the Halawa area is slated to occur within a radius of one-quarter mile from the proposed rail station at Aloha Stadium. The city’s draft plan draws that boundary, as it’s considered to be a comfortable distance for pedestrians opting to travel by elevated tracks rather than road.

Under the draft Halawa TOD plan, buildings up to 250 feet tall would be allowed in just one area bordering the rail station, while land beyond that but within a half-mile of the station would be limited to maximum building heights from 75 to 150 feet.

A developer is now asking the city to make an exception to the boundary lines for construction of a pair of towers — 250-feet and 276-feet tall, respectively — on land where the height limit is 150 feet. In exchange for concession, the developer is dangling potential opportunity to help ease Oahu’s affordable housing backlog.

City leaders certainly should be sizing up and seizing opportunity to build affordable units near the 21 stations dotting the planned 20-mile rail line. But members of the Aiea Neighborhood Board have raised valid concerns about tighter density and more traffic.

Proposed density is 5.6 square feet of building space for every square foot of land — more than twice as compact as the 1.9 limit under existing and proposed TOD zoning. Also, the developer wants to provide about 600 parking stalls for the project’s 524 homes, or about 1.2 stalls per unit.

The area surrounding the stadium — a mix of residential and commercial development as well as tourist attractions tied to Pearl Harbor and military uses — is already often traffic-clogged. So, it’s understandable that neighborhood board members would balk at the prospect of losing elbow room.

The arrival of a viable rail line, however, could change that. With enough people opting for train tickets, rail holds potential to effectively ease Oahu’s stubborn traffic congestion problems. TOD should facilitate this direction by folding in plans that tie pedestrian and bike paths from housing and other development to rail stations.

In the case of this proposal — pitched by developer Halawa View Housing Partners LP — the transition to transit should be nudged along by trimming the plan for parking spaces to one stall per unit.

Yes, some of the proposed towers’ residents might still cruise already crowded streets for a curbside spot to park their second or third vehicle. But it’s a good bet that others would forgo that headache, along with the yearly expenses strapped to owning multiple vehicles, to give public transit a go.

Other changes discussed for Halawa include state plans to level the aging stadium, replacing it with a scaled-down facility. Surrounding acreage on that site could be revitalized with commercial and residential construction, including affordable housing units, in tandem with TOD neighborhood design.

For several years now, Honolulu Hale has touted rail construction as a wonderful window to increase Oahu’s affordable housing inventory. It makes sense for the city to pursue high-rise options, rather than eating into land designated for agriculture.

Halawa View Housing plans to seek low-­income housing tax credits from the state’s Housing Finance and Development Corp. If granted, the towers would be rental apartments for residents earning no more than 60 percent of Honolulu’s median income — a demographic in critical need of units.

If unable to secure credits, the towers would be condos with just over half the units sold at prices affordable to households earning 80 to 140 percent of the median income. Remaining units would be sold at market prices.

Given that an estimated 24,000 affordable units are needed to meet Oahu’s demand, with most of it at or below the 80 percent mark, the city needs to push hard for rentals-filled towers. It also should put in place a no-dice policy for market-priced housing units in any TOD-related concession, especially when more zoning waivers or variances are involved.