The purpose was to provide a safer driving environment; prevent an increased number of crashes; continue the ongoing upgrade of State Highway 6; and improve the safety and efficiency of the road.
"State Highway 6 is the major strategic highway from Blenheim to Invercargill via Frankton and the West Coast," the notice of requirement said.
"As such, it is a major strategic highway for the lower South Island and vital to the social, economic and cultural wellbeing of the Otago region.
"Right-turning vehicles from Peninsula Rd currently join the state highway at the bottom of a dip and have to climb a crest before encountering a level road.
"This results in low travel speeds for turning heavy vehicles and the possibility of nose to tail accidents.
"The poor sight distances at the intersection make the area unsafe for both users of the State Highway and Peninsula Rd.
"Thus the option proposed will improve the safety along the affected section of State Highway 6 and Peninsula Rd."
The proposed work would increase the sight distance at the intersection by decreasing the gradient of the road and replacing a U-bend with a single radius curve, leading to an "optimised T-intersection".
The application said the existing state highway would be raised by about 3m near the intersection, while the state highway crest curve south of the intersection would be lowered by the same.
Peninsula Rd would also be realigned at the intersection, moving it by 50m, which would remove the tight U-bend and give an improved approach alignment to a T-intersection.
While there had only been "one non-injury-type accident" reported between 2002 and 2006, which was insufficient to justify improvement, it was noted the tightness of the U-bend required southbound heavy traffic and buses to encroach into the opposing lane to negotiate the turn from Peninsula Rd on to State Highway 6.
"It is possible the low crash rate is because local users make allowances for unexpected oncoming traffic."
Transit noted Peninsula Rd was largely used by "locals who generally have local knowledge".
"The Kawarau Falls Station may well cause more tourists to use the intersection, unaware of the likelihood of meeting traffic head on."
Kawarau Falls Station, which is under construction, has access to State Highway 6 for construction traffic as a condition of its resource consent, but that was unlikely to continue to be authorised once the construction phase of the project was completed.
"Projected vehicle generation from the proposed Kawarau Falls Station development results in peak increase of traffic of 4356 vehicles per day from the 756 visitor accommodation units planned for the site.
"The development also has allowances for 22 bus parks to transport and deliver vehicles to and from the development.
"Southbound traffic turning right into State Highway 6 from Peninsula Rd is considered to be the most hazardous traffic movement at the intersection, with 5% to 10% carrying out this manoeuvre.
"Modelling of projected traffic volumes at the intersection predicts two serious accidents in a five-year period, one involving a bus and one involving a car.
"The significant increase in traffic volumes predicted from the predicted growth of development in the area - which includes a projected 3000 houses at Jacks Point - and the substantial development at Kawarau Falls supports the likelihood of such accidents occurring with the current road configuration.
"In this case, the modelling of crashes based on projected residential and tourist growth provides the necessary justification for carrying out the proposed works, rather than an accident history at the intersection."
Construction was expected to take six months.
The public has until March 5 to make a submission on Transit's notice of requirement, which can be viewed at Lakes Environmental.
