Residents and officials offered praise and raised concerns after the long-awaited Nanakuli contra-flow lane opened Wednesday.

The concerns prompted the state Department of Transportation to look into both structural and operational changes for the 1.5-mile stretch of Farrington Highway from Piliokahi Avenue to near Nanaikeola Street.

The new contra-flow lane seeks to ease a traffic bottleneck in the corridor by repurposing one eastbound lane to allow for three Waianae-bound lanes and one town-bound lane during the weekday afternoon rush hour, from 4 to 7 p.m.

Residents traveling west Wednesday reported a shorter commute home, with some saying traffic flow resembled a weekend afternoon rather than rush hour. State Rep. Andria Tupola (R, Kalaeloa-Ko Olina-Maili) said many residents were pleasantly surprised that their westbound commute was cut in half. State Sen. Maile Shimabukuro (D, Kalaeloa-Waianae-Makaha) agreed, adding that one Waianae Coast resident said she was able to get home from town by 4:45 p.m. and spend more time with her family.

“For some people they’ve never seen no traffic going westbound at those hours ever,” Tupola said. “I do think it’s worth it.”

But the legislators and other residents agreed there were several problems, particularly with eastbound congestion, that require adjustments.

Kyle Okimoto, whose family owns Waianae Store and Nanakuli Super, said it took him an extra 35 minutes to drive from Maili Point to Nanakuli at 6:30 p.m. Wednesday and that it took an hour longer for one of his workers to get to Ewa Beach.

“It’s hurting people trying to get out of Waianae,” Okimoto said. “Although it has good intentions, I don’t think this contra-flow lane is going to work.”

Ed Sniffen, who heads DOT’s Highways Division, said crews will monitor the project for a week before making any structural changes, but the department is looking at operational fixes.

He said the department is considering extending the contra-flow lane farther west to Lualualei Naval Road to give eastbound drivers more space to merge from two lanes to one. He said his crews drove the route four times and reported the longest commute time was 55 minutes from Maili Point to Piliokahi Avenue, adding that they expected the backup to last a little more than an hour.

Another solution could be to close the contra-flow lane earlier, at 6:30 p.m. Sniffen said westbound traffic died down at about 6:15 p.m. Wednesday.

He said that drivers making illegal turns out of Kalanianaole Beach Park, formerly named Nanakuli Beach Park, added to the congestion. He said stationing a police officer or worker at the beach park should deter drivers from making those turns. DOT reported there were 65 drivers seen making illegal left turns at Nanakuli Avenue on Wednesday. Sniffen encouraged drivers to follow the road signs to ensure that the route is safer and more efficient for everyone.

“Anytime we give more lanes in one direction and take away from the other, we know there’s going to be some impacts,” Sniffen said Thursday. “I thought for the first day of the contra-flow, there were definitely things that we need to tweak, definitely things we need to focus our enforcement on, but I think it went very, very well.”

Some residents were upset that eastbound left turns at Nanaikeola and Helelua streets and Haleakala and Nanakuli avenues were closed, forcing them to use a detour at Laumania Avenue through Pohakunui Avenue to Piliokahi Avenue. Sniffen said there were 116 vehicles that used the detour during the first two hours of the contra-flow operations but almost none during the last hour.

Tupola and Shimabukuro said opening up parts of the Waianae Coast Emergency Access Route, a series of roadways that bypass Farrington Highway during emergencies, could help eastbound residents get through quicker. Another suggestion was to improve and open a dirt path at Depot Beach Park for eastbound buses and emergency vehicles.

Richard Landford, chairman of the Nanakuli/Maili Neighborhood Board Transportation Committee, said the biggest problem was the lack of police presence, adding that it was “the most detrimental thing that was missing.”

DOT had requested five special-duty police officers be stationed along the contra-flow route, but there were none Wednesday. Sniffen said there will always be five trained flaggers stationed along the route for traffic control. He said no officers signed up for the contra-flow assignment yet but that he is working with the Honolulu Police Department to get officers.

An HPD spokeswoman said Thursday the department is trying to fill special-duty officer positions, but on-duty officers will assist if needed.

Shimabukuro said it will take residents time to get used to the changes.

“Even if it takes some time to work out the kinks, I’m just so happy to see that something’s happening,” she said. “Coming home, I think, was definitely a big improvement, which is the majority of the traffic at that hour. I think in time hopefully it (eastbound traffic) won’t be so bad. I guess time will tell.”