The diggers will soon move in to the bottom of the Hutt Valley's Haywards Hill to begin work on a $43-million interchange that will do away with the current traffic lights.
The New Zealand Transport Agency has given the contract for the intersection work to Downer Engineering to upgrade the intersection of State Highways 2 and 58, which goes across to SH1.
The interchange will be similar to Lower Hutt's Dowse interchange, but also feature a carpark with pedestrian access to the nearby Manor Park train station and "a unique set of cycle bypasses in both directions".
The bypasses will remove the need for SH2 cyclists to cross the traffic lanes when passing through.
Ground preparation is expected to begin next week and work should take two years, NZTA Wellington highways manager Neil Walker says.
"People who use this intersection frequently will know that it can be a real bottleneck, and that there's also a number of crashes and near misses when drivers get impatient or make mistakes," he said.
"This project will effectively put those problems behind us."
Mr Walker said there was a strong support from locals for the upgrade and Upper Hutt mayor Wayne Guppy said he welcomed the project.