The Hawai'i County Department of Public Works will upgrade the traffic signals at the

intersection of Kuakini Highway and Kamehameha III and Walua roads on Saturday, a news release said.

The upgrade is the first of several short-term improvements planned by the county for

the proposed opening of the northern portion of the Mamalahoa Highway Bypass this summer.

Once the traffic signal is upgraded with split phases, motorists traveling on Kamehameha III and Walua roads will have separate green lights, instead of sharing a green light.

"Currently, motorists coming up from Kamehameha III making a left turn onto Kuakini must wait for Walua drivers," said Ron Thiel, chief of the county's traffic division. "Now drivers on Kamehameha III and Walua will each have their own green light, when the other three approaches have red lights."

The traffic signal upgrade is expected to take all day Saturday and any traffic interruptions will be directed by the police. First the drivers will see flashing lights beginning about 9 a.m. After an hour or so, the signal lights will be turned off completely and two police officers will direct traffic for the duration of the upgrade. There will be two caution signs advising the drivers, "Be Alert — New Traffic Pattern Ahead." One sign will be located approximately 300 feet mauka of the Walua Road intersection approach and one located on the Kamehameha III approach.

"We are responding to the concerns of the residents of Keauhou and improving this intersection now," Thiel said.

The county plans to open on a trial basis the northern portion of the Mamalahoa Highway bypass from the end of Ali'i Drive in Keauhou to the bottom of Haleki'i Street in Kealakekua. The bypass will be open from 3:30 to 6:30 p.m. Monday through Friday for south-bound traffic only. The Hawai'i County Planning Commission recently approved the county's traffic mitigation plan for the Mamalahoa Highway Bypass. The Hawai'i County Council will be asked to amend the county ordinances to allow the use of Haleki'i Street in Kealakekua, in conjunction with the opening of the northern portion of the Mamalahoa Bypass.