The state Department of Transportation is gearing up to begin work replacing three bridges on O'ahu's Windward Coast, maintaining that upgrades are needed to improve safety and that traffic tie-ups will be few.

Next on the list of more than a dozen bridges slated for replacement through the state's ongoing $77 million project is Kokololio Bridge, between La'ie and Hau'ula. Construction of the estimated $4.4 million project is expected to begin in October or November and take 15 months to finish.

"It's not to say it's going to fall apart tomorrow," DOT spokesman Scott Ishikawa said of the 73-year-old Kokololio Bridge.

Ishikawa warned, however, that if any of the Windward bridges fail, residents could be faced with long commutes to town.

"We're just saying we want to take care of it now. We don't want to end up with a Waimea Bay, where people were forced to travel halfway around the island just to get into town," he said.

In 2000, tons of rocks fell from the cliffs above Waimea Bay closing Kamehameha Highway for two months as a $7.5 million mitigation project was conducted. Circle-island tour buses and local businesses were especially hard hit by the closure.

In all, 16 O'ahu bridges will be replaced, including 11 on the Windward Coast, according to DOT plans initiated two years ago with state and federal funding. Many of the bridges are more than 50 years old and were constructed when traffic was lighter and vehicles weighed less. None meet modern standards for crash strength, width, weight or seismic loads.

Thousands of people use the Kokololio Bridge daily in and out of Hau'ula and La'ie, and even more travel the Kamehameha Highway on weekends as bumper-to-bumper traffic crowds the highway to the North Shore.

The bridge is especially dangerous because it has only a narrow 1-foot shoulder for pedestrians, Ishikawa said. The state's plan calls for replacing the two-lane bridge with wider 12-foot lanes, 8-foot shoulders and a 5-foot wide protected walkway and bikeway on its mauka side.

Noel Bragg, a La'ie resident, said rising traffic flow in the area underscores a need for bridge upgrades. However, he contends that in the long run the state's plan may be wasting money.

"It would be a lot cheaper to build a walkway outside the bridge because some day we'll have to take that new bridge which is also going to be only two lanes and make it four lanes," said Bragg at a Ko'olau Loa Neighborhood Board meeting last week.

Other residents at the meeting were concerned about the prospect of traffic congestion if work on the two other upcoming bridge replacement projects overlap that for the Kokololio Bridge.

The state has $10.5 million earmarked to replace the South Punalu'u Bridge, with work beginning in late 2006. The $9.2 million North Kahana Bridge replacement work is set to start in the fall. Both are projects expected to be completed within 18 months. The South Punalu'u Bridge and the North Kahana Bridge are about two miles apart, and the Kokololio Bridge is about three miles from Punalu'u.

Ishikawa said the contractors would build temporary bypass roads adjacent to the old bridges, eliminating traffic tie-ups.

The state recently completed two bridge projects in Kahuku in which work was under way simultaneously. Bypass roads were used to effectively minimize traffic interruption, said Don Hurlbut, Kahuku resident and Ko'olau Loa Neighborhood Board member. The $7.1 million Kii Bridge and Hospital Culvert, just hundreds of feet apart, were completed in December.

"We had no problems," Hurlbut said, adding, "I absolutely do not anticipate any problems with the three projects."

Still, the thought of any potential traffic jam leaves some area residents feeling a bit leery. The neighborhood board hopes to meet with managers of the three projects in September to discuss traffic concerns, said DeeDee Letts, Ko'olau Loa Board chairwoman.

"We want to look at the cumulative impacts and we want some kind of commitment from them that if they start the Kokololio Bridge and there are significant traffic delays and problems, they won't start the rest of them until that one is finished," Letts said.

Also, Letts said she wants to make sure work is not scheduled for weekends.

"Weekends are our all-day rush hour with everybody trying to get out for recreational activities," she said.