2 vehicles plunge off H-1 Freeway in one month period

HONOLULU (KHON2) — A 57-year-old woman died after an overnight crash near the airport Wednesday night.

Initially HPD said the woman was driving eastbound, but four days later HPD sent a correction stating that the woman was traveling westbound on the H-1 Freeway at a high rate of speed, when she collided with the concrete guardrail. HPD said the vehicle came to rest on Aolele Street below.

Police said the woman was wearing a seatbelt at the time of the crash.

On Sept. 16, a 28-year-old man was taken to the hospital in critical condition after a 19-year-old woman crashed into him after driving the wrong way on the Hickam overpass.

HPD said the man’s car struck the concrete barrier and went airborne coming to rest on its roof on the H-1 West Freeway/Arizona Memorial off-ramp below.

No pedestrians or other vehicles were involved in the crash after falling. The concrete barriers along the freeways are called jersey barriers, and they’re used across the mainland.

“They’re absolutely safe in those areas of the freeway,” explained Hawaii Dept. of Transportation Director Ed Sniffen. “They are compliant with our federal requirements and when people are traveling the speed limit in that area they’re very very safe.”

“It’s a sad situation when you see any fatality, but its very rare that vehicles go over, I can think of three that have occurred in the many years I’ve been at DOT, but we of course want to make things safer so we want to make sure we minimize speed going into these areas and minimalize the potential for people to pass away like this,” he continued.

“The height of the barriers is about 30 inches plus or minus,” explained Lin Shen, associate professor of Civil, Environmental and Construction Engineering with a specialty in concrete. “The main function is to reduce the possibility of a head-on collision.”

Shen said the height, speed and angle of a car when it crashes matters.

“If the angle of impact is small then the chance of going over the barrier would be low, but if you have a head-on impact at a 90 degree angle, the chance of flipping over would be much higher,” he explained.

He said the taller the barrier, the better to prevent cars from flipping over.

Median barriers across the H-1 Freeway have been raised over the years but they were to prevent glare from the opposite lanes of traffic.

A former University of Hawaii engineer said only a proper wall could prevent a car from flipping off the freeway onto the road below.

Shen said there are concrete barriers that can withstand a terrorist attack and can prevent a large truck hitting it straight on at 50 mph from flipping or falling over the concrete barrier, but they are extremely costly.

Sniffen said to raise the height of the barriers already in place would be extremely costly.

“You can’t just add onto a concrete barrier, you would have to take it down and reconstruct it because the strength comes from its connection to the base,” Sniffen explained. “So the foundation has to be upgraded and has to go deeper, the width of the barrier at the bottom that has to resist the sheer from the vehicle has to get bigger as well before you can build it straight up.”