Yesterday's closing of the H-1 Freeway and subsequent traffic jam highlight the limitations of Honolulu's transportation infrastructure, according to a University of Hawai'i traffic specialist.

"Something like this really shows how vulnerable we are to a major catastrophe," said Pans Prevedouros, a professor of civil and environmental engineering who specializes in transportation issues. "We don't have any roadway redundancies, and we don't have an integrated contingency plan to deal with something really big on our roads."

After the state closed the freeway yesterday afternoon, all west-bound traffic was diverted to smaller highways and streets already operating near rush-hour capacity. With few alternatives available, traffic quickly backed up for miles on the freeway and feeder streets.

Those streets were often clogged by fender-bender collisions between frustrated motorists and other drivers who simply pulled over to the side to wait out the traffic.

Drivers reported abnormally heavy traffic on thoroughfares such as the Likelike Highway, Pali Highway, Moanalua Freeway and Kamehameha Highway.

To accommodate the diverted traffic, traffic signal times on Kamehameha Highway and Moanalua Road were increased to their maximum, said Tai Fukumitsu, a signal engineer at the city's traffic management center in Honolulu.

On Kamehameha Highway that meant the lights stayed green for up to four full minutes, he said. Normally, the lights change every 120 seconds during rush hour.

Monitoring the traffic flow on live video feeds, Fukumitsu said Kamehameha Highway was busy but moving. It was slower going on Moanalua Road, which is a little narrower and has more residential traffic in its mix, he said.

City officials planned to monitor the traffic through the night and continue to adjust the signal timing as needed, Fukumitsu said.

He advised motorists heading to town today to leave much earlier or later than usual to avoid the biggest backlogs.

The situation highlights the long-standing issue of limited options on O'ahu.

"In an evacuation or catastrophe-type situation you want to be able to use all eight or 10 lanes of the freeway. In some states like Florida, they have plans in place where they can even reverse all the on- and off-ramps to go in one direction. In Hawai'i we don't have a plan to do that," Prevedouros said. "Contingency plans are critical, but right now we're limited to ad hoc steps."

Even with the best of planning, Hawai'i's freeways don't lend themselves to major contraflowing plans because traffic is relatively equal in both directions, he said.

"This highlights the necessity of developing some redundancy in our traffic systems," said Prevedouros, who has been a vocal advocate of developing public-private partnerships that would build a private toll road on O'ahu.

He is scheduled to talk about "Real Solutions to Traffic Problems" in 'Ewa tonight. In the presentation, Prevedouros said he plans to explain the rapid growth elsewhere in privately funded roadways, which can be built quicker and for less money than publicly funded projects.

Although city officials last night changed the timing of some traffic signals to accommodate freeway traffic diverted to smaller roads, Prevedouros said that offered only limited help.

"You need a fully integrated plan that's put into motion right away, using all the intelligent transportation systems that are available. Sometimes there are 10 or 20 different things you can do all at once. In general, we haven't yet developed that type of master plan to deal with situations like this," he said.

Reach Mike Leidemann at mleidemann@honoluluadvertiser.com.