comscore Safety standards determine length of coned-off section of road | Honolulu Star-Advertiser
Kokua Line

Safety standards determine length of coned-off section of road


Question: We got on Pali Highway from Kailua going toward Honolulu on Monday, March 28. One lane was coned off all the way from the beginning of the highway to the tunnel. There were no workers or activity. When we went through the tunnel at the other end, there suddenly were workers knocking down trees. What possible concept exists to block off one lane all the way through the tunnel with nothing going on?

Answer: Highway safety.

That’s the concept behind the "seemingly long lane closure," a spokesman for the state Department of Transportation said.

He explained that the length of lane closures is determined by the U.S. Department of Transportation’s Manual on Uniform Traffic Control Devices, which defines national standards for traffic control on all public streets, highways, bikeways and private roads open to public traffic.

Required lengths are calculated using formulas based on a road’s speed limit and lane widths.

"Although the work site you mentioned was just outside the Honolulu side of the Pali Tunnels, the winding course of the highway approaching the tunnels poses the complication," the spokesman explained.

With a 45 mph speed limit, the manual’s standards require a 720-foot taper where two lanes of traffic, including the shoulder, can merge safely into one, he said.

"From the Kailua side, the only point approaching the tunnels where this merge can be accomplished safely is on the straight section between Castle Junction and the beginning of the hairpin turn," he said.

"From that point on, the road become a series of six curves all the way to the tunnels. At 45 mph a traffic merge in this winding section would require rapid maneuvers that could endanger motorists."

He also explained that, also for highway safety reasons, traffic merges generally are not placed inside highway tunnels because of diminished visibility and limited space.

"Although the length of this lane closure might seem inconvenient, its purpose (was) to minimize the potential for high-speed traffic accidents and to ensure the safety of motorists," the spokesman said.

Question: My concern is about Kahekili Highway where they put in a border to prevent landslides. The water sprinklers are not working — four are not working and one is just dribbling out. Can you let whoever is responsible know?

Answer: We passed your concern on to the state Department of Transportation, which alerted its Highways Division Maintenance Branch for inspection and repairs.

Next time, you can call the highways complaint hot line at 831-6714.

That’s the number Oahu motorists can report state highway maintenance issues, including broken sprinklers, lighting problems, overgrown landscaping, potholes or graffiti.


To the two strong, really good-looking guys who helped me get my 6-foot-3, 180-pound friend from his wheelchair into my car at the airport. I was unable to get him at the curb even though a fine gentleman waiting to be picked up offered to assist. I then drove to the tour bus parking lot at the end of Hawaiian Airlines so it would be easier. Out of the blue, the gentleman showed up in a van driven by the person picking him up. They both helped get my friend into the car and smiled as they drove off in a van with an emblem of "Kamehameha Schools." The aloha was so real and the reason Hawaii is so really beautiful. My thanks to all the Hawaiian people sharing their true aloha. — Amy

Write to "Kokua Line" at Honolulu Star-Advertiser, 7 Waterfront Plaza, Suite 210, 500 Ala Moana Blvd., Honolulu 96813; call 529-4773; fax 529-4750; or email

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