In an effort to ease major eastbound traffic congestion created by the opening of a contra-flow lane on a stretch of Farrington Highway in Nanakuli during the afternoon rush hour, the state Department of Transportation has made an adjustment by extending the contra-flow about three blocks in the eastbound direction to allow more space for traffic to merge.

The move came after opening a contra-flow lane Wednesday created significant backup in the eastbound direction. The long-awaited contra-flow project on the four-lane highway takes away one of two eastbound lanes to allow for three Waianae-bound lanes from Piliokahi Avenue to near Nanaikeola Street from 4 to 7 p.m. weekdays.

Ed Sniffen, who heads DOT’s Highways Division, said Friday that extending the eastbound route about 400 feet east of Lualualei Naval Road should help drivers merge more efficiently to one lane from two. He said the department would gather data to determine if the extension made a difference.

“No matter what we do, because we went from two lanes to one in the eastbound direction, there’s going to be an extension of time,” he said.

Sniffen said it takes an average of 11 to 14 minutes to drive through the contra-flow route in either direction, adding that westbound drivers have reported saving 20 to 25 minutes in commute time. However, he said he expected the eastbound backup to be a little more than an hour and that his crews reported a commute time of 48 minutes from Maili Point to Piliokahi Avenue on Thursday, compared to 55 minutes on Wednesday.

State Rep. Andria Tupola (R, Kalaeloa-Ko Olina-Maili) said Friday that the eastbound extension did not seem to make a difference. She said the drive from Maili Point to Piliokahi Avenue took about 30 to 40 minutes Friday, the same as it did on Wednesday.

“I would say eastbound was about the same,” Tupola said. “It’s definitely backed up to the same spot.”

Sniffen said an additional measure to help deal with eastbound congestion was having on-duty police officers stationed at Helelua Street and Haleakala and Nanakuli avenues Thursday and Friday to monitor traffic flow. DOT has restricted eastbound left turns at those three intersections and at Nanaikeola Street and have directed drivers to use a detour at Laumania Avenue through Pohakunui Avenue to Piliokahi Avenue. He said there was only one driver who made an illegal left turn Thursday, compared to the 65 drivers Wednesday at Nanakuli Avenue, which contributed to the congestion.

Drivers coming out of Kalanianaole Beach Park, formerly Nanakuli Beach Park, were allowed to turn only right on Friday. Eastbound left turns at Lualualei Naval Road were allowed.

Residents and officials had raised concerns about the lack of police presence on Wednesday after DOT said it requested five special-duty officers but none had agreed to work.

Officials and residents had also recommended opening up parts of the Waianae Coast Emergency Access Route — a series of roadways that bypass Farrington Highway during emergencies — for eastbound drivers and using a dirt path near Depot Beach Park for eastbound buses and emergency vehicles.

But Sniffen said the environmental assessment for the emergency access route does not justify daily operations. He added that any work and changes to areas other than paved roads and streets would need to get environmental clearances, which could take more than a year.

Sniffen is expected to make a presentation at Tuesday’s Nanakuli/Maili Neighborhood Board meeting on the contra-flow lane and other transportation projects.