Mayor Kirk Caldwell, who has spent much of his time in office struggling with repeated rail project crises, got a chance last week to tout one of his administration’s clearest victories — keeping a campaign promise to fix a big chunk of the city’s dismal, pothole-plagued streets.

Shortly after taking office in 2013 he announced an aggressive five-year campaign to repave Honolulu’s worst 1,500 lane-miles — 43 percent of all city-owned roads.

During a press conference Friday in St. Louis Heights, Caldwell declared that crews didn’t just hit that mark but surpassed it, repaving 1,774 total lane-miles in that time frame for about $550 million.

Cory Lum/Civil Beat

“We tackled the goal we said we would do,” Caldwell said as heavy repaving trucks rumbled up Robert Place behind him. “Part of it is just getting contracts out and getting enough head of steam to get these things done.”

But the story doesn’t end there.

It remains unclear whether Honolulu taxpayers will get as much life out of that half-billion-dollar repaving investment as they could because of a limited budget for pavement preservation.

While the city has surged in repaving, it has lagged in mapping out the full maintenance needs across its entire 3,500-lane-mile street grid to seal out water, block the sun and preserve pavement life.

And with the limited dollars, it’s not certain when that evaluation will be finished.

‘The Earlier The Better’

So far, none of the nearly 1,800 lane-miles repaved in the last five years have been treated with slurry seal, seal coat or other materials routinely used in other cities to extend the life of their roads, officials say. Such treatments often get applied within several years of repaving to be most effective.

“The earlier the better,” said Larry Galehouse, founder and director-emeritus of the Michigan State University-based National Center for Pavement Preservation. “You want to put these treatments down fairly soon after a road is paved.”

City officials still don’t have a grasp on which of the repaved streets qualify for crack seal, slurry seal or seal coat, or how often they should be treated.

“That’s a question that we can’t answer yet,” Department of Facility Maintenance Director Ross Sasamura said Monday.

Some other city roadways have started getting slurry seal and preservation treatments. But officials say they lack a complete pavement-management schedule with data to tell crews which streets across the island should get which treatments and how often.

A recent pavement task group for the Federal Highway Administration flagged that objective data as essential to any “world-class” preservation program. The task force’s No. 1 recommendation for success was “dedicated and consistent funding.”

The city does provide consistent funds, but it’s likely not enough to cover the entire island’s needs. Since 2014, Sasamura and his department have used the annual $3 million available to put down crack seal, slurry seal and seal coat in a handful of neighborhoods: Nuuanu, Aliamanu, Aiea, Salt Lake and Waipahu.

Within those pockets, the city reports having slurry-sealed 131 lane-miles, seal-coated 115 lane-miles and applied more than 1 million linear feet of crack seal.

More Data Needed

To get a better maintenance picture, officials say they need to update Honolulu’s “pavement condition index” — a survey of local roads and their condition. A civil-engineering firm conducted the survey in 2012 using imaging technology similar to “street view” on Google Maps.

Sasamura said they’ve started the update but can only make progress as more money becomes available.

They hope to collect more survey data in fiscal year 2019.

The city is also awaiting the results of a years-long pilot program developed by Ricardo Archilla, associate professor of civil and environmental engineering at the University of Hawaii Manoa. The program studies how crack seal performs on streets in Pearl City and slurry seal performs on Waipahu streets.

Archilla said he aims to have his report ready early next year.

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Slurry seal and seal coat are basically asphalt mixes that are thinly spread across a road to stave off deterioration. “At the end of the day, it’s no different,” Galehouse said.

Often, work crews will fill large cracks in the road with another rubbery substance — crack seal — before they coat the whole surface with slurry seal later.

These treatments cost a fraction of what it costs to repave, and if done right they can significantly slow the crumbling seen on many Oahu streets. Slurry seal typically extends a road’s life up to six years while the coarser, stonier seal coat can extend it up to eight years, Galehouse said.

Some mainland agencies have started putting those materials down the same year a road is paved, he said, adding that would go a long way toward preserving asphalt roads on an island drenched in sun and rain.

“The whole idea is, you’re going to manage,” Galehouse said. “You can’t wait for your roof to leak before you repair it.”

Archilla likened the treatments to changing the oil in your car.

Sasamura gets it too — and he’s offered his own metaphor. The Oahu resident drives a red 1993 Chevrolet Suburban K2500 truck that’s lasted well past its normal life through persistent maintenance. In 2016, Sasamura said he wanted to apply that lesson to Honolulu’s deteriorating roads.

Behind The Curve

Part of the problem is that Honolulu only started using the materials recently, beginning with 10 lane-miles of slurry seal in 2010 and 11 lane-miles in 2011. It’s playing catchup on road-maintenance tools that industry experts say have been around since at least the 1970s. Honolulu put down its first two lane-miles of seal coat in 2015.

“The real issue now is to see how the pavement is aging,” Sasamura said of that years-long process at Caldwell’s press conference.

In Waipahu, city maintenance officials had planned to slurry-seal 191 street segments, according to a list that Sasamura provided. But the limited funding contributed to them canceling 77 of those.

“We’re working within the funding constraints that we have available to us,” he said Monday.

Cory Lum/Civil Beat

Not all roads are candidates for such life-extending treatments. Typically slurry seal is applied to the smaller streets that don’t get as much traffic. The 2012 survey found only 465 city lane miles that would benefit from slurry seal and other treatments.

But that number will change once the new survey’s finished, Sasamura said. Some streets that were flagged in 2012 will have degraded to the point where slurry will no longer help. On the other hand, some streets repaired in the extensive repaving work will be “prime candidates,” as Sasamura put it. He anticipates his department will need a bigger budget to cover more work.

“We need to assess how much more we’re going to need,” Sasamura said. “The $3 million is the starting point. ”

Securing more money could prove difficult in a tight budget environment, where the city is stretched thin to cover its collective-bargaining agreements and debt payments. “It’s just a matter of prioritizing and getting good data in so we get good contracts out,” Caldwell spokesman Andrew Pereira said Monday.

Meanwhile, the city aims to keep the repaving push going. It plans to fix streets in Aeia Heights, Campbell Industrial Park, Kalaeloa, Manoa and downtown in 2018, Caldwell said.

The mayor also mentioned slurry seal’s advantages.

“It can prolong the life, otherwise we’re back doing it again after 10 or so years and really this should be an ongoing, forever effort,” Caldwell said Friday. “It should never be allowed again to get to the point where it was when we came into office.”