"To achieve that we came up with four core values.
"The first one was care.
"We needed to ask ourselves, on any decision made on this project, is this a caring decision?
"The second one was innovation.
"We wanted to be innovative.
"Testament to that is the bridge [over the Waikanae River] we're standing on now.
Integrity was third.
"We needed to show integrity all along, be honest with everyone, be open, and earn the respect and integrity of the community."
And then there was resilience.
"It's as a result of us showing resilience that we're able to stand on the bridge today."
He noted new standards had been set in terms of safety.
There had only been a few injuries over the five million hours worked.
"We've had no fatalities on the road and the last time someone was injured on this job, and not coming to work the next day, was March 2015."
Mr Palm said, "I want to thank our workers.
"We've had over 5000 workers who have constructed this expressway."
And Mr Palm thanked the community, especially the leaders.
"We've been so impressed by your engagement and positive drive to reach the best solutions for both the community and the project.
"We hope everyone enjoys using the expressway as much as we have enjoyed building it."