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UH engineer has
ideas for improving
H-1 traffic flow

Panos Prevedouros calls for
better use of on- and offramps from
Koko Head Avenue to Middle Street

By Harold Morse
Star-Bulletin

Traffic flow in the Ewa-bound lanes of the H-1 freeway can be improved quickly at low cost, according to a University of Hawaii engineering professor.

His solutions call for no double-decking or major widening, but simply better use of freeway on- and offramps from Koko Head Avenue to Middle Street.

Panos Prevedouros, associate professor and graduate program chairman of the UH Department of Civil Engineering, has been studying traffic flow on the H-1 since 1996, under contract with the state Department of Transportation. The $188,000 study ends in mid-2001.

"We really don't know if we'll implement (the recommendations) until we see the end of the study," department spokeswoman Marilyn Kali said. "We're not sure what the conclusions will be."

Experimented in 1997

Prevedouros also has looked at Koko Head-bound traffic, but has only come up with preliminary conclusions.

For now he's concentrating on traffic headed in the opposite direction.

His quick fixes were simulated in detail using sophisticated surveillance cameras, detectors and other equipment under real conditions, he said. Utilizing this data, a model was set up to do alternative analysis.

Although more than 100 action scenarios were put in final form, only a few have so far made the cut.

One was a two-week experiment in 1997 that temporarily redirected traffic from the Lunalilo on-ramp to the Vineyard offramp, Prevedouros said.

Vehicles on the Lunalilo on-ramp were prevented from merging into freeway traffic by traffic cones and redirected to the Vineyard offramp. The aim was to prevent a bottleneck at Lunalilo so as not to slow traffic already on the freeway.

Motorists who still wanted to merge onto the freeway could utilize on-ramps from Punchbowl Street, Aala Street or the Palama end of Vineyard.

There were difficulties with cones spilling all over the lanes during the two-week period, Prevedouros said. After the experiment the DOT suggested a different type of cone -- one embedded with a small prong to make it stick to the freeway -- might work better. Another possibility suggested was flashing lights to warn motorists not to merge onto the freeway.

From offramp to through lane

Prevedouros said permanently banning vehicles from merging onto the freeway from the Lunalilo on-ramp could reduce weekday traffic delays between 6 and 9 a.m.

During the 1997 experiment, Ewa-bound commuters saved about two minutes in travel time. It was thought this savings might be greater once motorists get familiar with the rerouting.

Another possibility suggested by Prevedouros is to extend the Likelike Highway offramp at the Kalihi Street underpass. The off-ramp would become a through lane, thus adding a fourth lane to the freeway as it goes under Kalihi Street.

"The freeway (now) drops suddenly from four lanes to three lanes, and then it becomes again four and five lanes," Prevedouros said.

His third recommendation involves afternoon ramp metering at the Alexander Street on-ramp. From 2 to 6 p.m., a ramp meter using green and red lights would let cars enter the freeway at short intervals, he said.

Rebuild Manoa interchange

A fourth possibility is to reconstruct the mauka side of the University-Manoa Interchange, essentially the link between the H-1 and University Avenue, Prevedouros said.

Prevedouros also has suggestions to improve Ewa-bound central city traffic outside the freeway:

Coordinate traffic signals along Vineyard Boulevard.
Eliminate left turns from the Koko Head-bound lanes of Vineyard Boulevard at its intersection with Punchbowl Street from 6 to 9 a.m.
Eliminate left turns in both directions on Vineyard Boulevard at Liliha Street.
Redesign the intersection at Pali Highway and Vineyard Boulevard to provide twin left turns in all four directions.

A long-term plan calls for a grade separation at Punchbowl and Vineyard, with Punchbowl going under Vineyard.

"That would really unclog a lot of traffic," Prevedouros said.

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Roadwork

Planned this week throughout Oahu:

LEEWARD OAHU

Ewa Beach

Fort Weaver Road from Farrington Highway to Hanakahi Street; and Farrington Highway from Piliokoe Bridge to Kahe Power Plant in the vicinity of Tracks Beach Park.

Waianae

Hakalina Road from Pahihi to Puhawai roads.

NORTH OAHU

Haleiwa

Haleiwa Bypass.

CENTRAL OAHU

Kunia

Vicinity of Kunia Interchange to Waikele Stream Bridge and from Kupuna Loop to Farrington Highway; Kunia and Fort Weaver roads; H-1 freeway ramps 5 and 5-B and all other ramps in Kunia Interchange; and H-1 freeway in the vicinity of Kunia Interchange.

Wahiawa

Kilani Avenue from Holoku Place to Ilima Street; and Mala and Ilima streets.

Mililani

Mililani Interchange; and Lanikuhana Avenue.

Waipio

Farrington Highway, Leoole to Awanui streets; and Paiwa to Leoku streets.

Waipahu

Waipahu Street from Amokii Street to Waikele Road.

Aiea

Moanalua Road from Punanani Channel to Pali Momi Street; Kaonohi Street between Alania and Kahapili streets; Kahapili Street to Kaonohi Street; Maohu and Heleconia places; and Akaaka, Ilee, Kulawai and Kaamilo streets.

Pearl City

Komo Mai Drive from Waimano Home Road to Hookupa Street.

HONOLULU

Foster Village

Halupa Street from Haloa Drive to Punihi Street.

Salt Lake

Ala Ilima and Likini streets.

Kalihi

Makuahine and Kalihi streets; Dillingham Boulevard between Waiakamilo Road and North King Street; Kamanaiki Street from Violet to Laulani streets; and Kapalama, School, Moani, Laulani, Puolani, Pahulu and Noe streets.

Liliha

Huli Street; and Vineyard Boulevard at Nuuanu Avenue.

Nuuanu

Kimo Drive Bridge; Kaohinani Drive from Kimo to Pelekane drives; Kahawalu Drive between Kaohinani and Niolopua drives; Kahawalu Drive; Ragsdale and Homelani places; Pali Highway at Waokanaka Street; Waokanaka Street to the Pali tunnel entrance; Pali Highway from Country Club Road to the tunnel entrance, including both roads to the lookout; Dowsett Avenue; Waokanaka Street; and Old Pali Road.

Chinatown

King, River and Bethel streets.

Kakaako

Kapiolani Boulevard; Keawe Street on Ala Moana, South and Queen streets, and Nimitz Highway and River Street to end at Hotel Street; and Coral Street from Ala Moana to Auahi Street.

Kapiolani

Harding Avenue from Kapiolani Boulevard to 1st Avenue; and Kapiolani Interchange.

Makiki

Keeaumoku and Heulu streets; and Piikoi at Lewalani drives.

Moiliili

Kahoaloha Lane from Kuilei Lane to South King Street; and Kuulei Street from Kahoaloha Lane to University Avenue.

Punahou

Spreckels Street.

Kaimuki

12th, Koko Head, 6th and Kaimuki avenues.

Waialae

Aha Nui Place; Ainakoa Avenue; Malia and Makaikoa streets; and H-1 freeway, Koko Head to 21st avenues.

Waikiki

Ala Wai between Ala Moana and Kalakaua Avenue; Ala Wai promenade; Kalakaua Avenue and McCully Street between Ala Wai and Kapiolani boulevards; and Kalakaua Avenue from Kaiulani to Kapahulu avenues.

Wilhelmina Rise

Maunahilu, Pakolu and Pili places; and Paula Drive between Maunahilu Place and Iwi Way.

WINDWARD OAHU

Kaaawa

Kamehameha Highway from Mahe Point to Lau Place.

Kahaluu

Ahuimanu Road; and Kialua, Hoopai and Poomau streets.

Hauula

Keala, Kawaipapa and Puuowaa roads; Waikulama Street; and Kamehameha Highway from Pipilani to Kaupau places.

Kailua

Kalanianaole Highway, Kamehameha Highway to Kapaa Quarry Road; Ililani Street from Mokapu Boulevard to Iliwahi Loop; Iliwahi Loop to Ilimano Street; Iliaina Street from Ililani Street to Iliwahi Loop and from Ilihau Street to end; Kailua Road at Kalaheo Avenue and on Aumoe Street; Kalanianaole Highway to Kawainui Bridge; Alahaki, Akaakaawa, Akamai and Akupa streets; Ilikaa, Akupa, Akahele, Akahelo and Nanaloko places; Akaakoa Street and Place; and Old Kalanianaole Highway.

Waimanalo

Kaaiai Street from Huli to Nakini streets; and Kumuhau Street from Waikupanaha to Mahailua streets.

Kaneohe

Keaahala Road from Anoi Road to Keaahala Place.

EAST OAHU

Kalani Valley

Kalaniiki Street and Kalanikai Place.

Hawaii Kai

Kalanianaole Highway from Nawiliwili Street to Sandy Beach Park Entrance; and from Hanauma Bay to Sandy Beach.