The $9 million project was sparked in the wake of safety concerns at both the old Watchman Rd intersection and the entrance to the airport off SH2.
Both intersections were deemed unsafe by the NZTA which has worked in with the Napier City Council and the Hawke's Bay Airport Authority to get the issue resolved.
The NZTA has injected $5.5 million into the project, the council $2 million and the airport authority $1.5 million.
Along with the roundabout, work on the new airport access road from Watchman Rd is well advanced as is landscaping of the immediate area.
Delays to travel can also be expected at the Pakowhai and Links Rd/expressway roundabout site.
Speed restrictions are in place and travel delays up to five minutes are likely.
The NZTA has advised commuter travellers using the stretch at peak times to consider using other routes.
Northbound traffic could access the expressway at Evenden or Omahu Rd roundabouts and southbound traffic either the Meeanee overbridge or SH50 through Fernhill.
Another option was SH2 through Clive.
The northern stretch of SH2 between Napier and Wairoa is the site of a string of work projects and travel times will be affected.
Temporary speed restrictions and stop-go signalling is in place at sites between Bay View and Putorino for surface repairs, Nuhaka to Putorino for sealing work and for a power pole replacement programme between Nuhaka and Tahaenui.
Contractors are also carrying out surface repairs and re-sealing around Te Pohue and Te Haroto on SH5 between Napier and Taupo and speed restrictions are in place.
Similar restrictions, along with traffic lights and a single lane system, are in place at the Tuki Tuki River Bridge on SH2 near Waipukurau where strengthening work is being carried out.