The 13 alternative route options are available for public viewing and comment on the NZTA website.

Thirteen alternative routes to the Manawatū Gorge have been laid out for the public to discuss.

The NZ Transport Agency put forward the options for an alternative road to State Highway 3 through the gorge at a meeting at the Palmerston North Conference and Function Centre on Monday.

The gorge has been closed since April after several slips crashed down and blocked the road.

DAVID UNWIN/FAIRFAX NZ The NZ Transport Agency has released 13 options for permanent alternative routes to State Highway 3 through the Manawatū Gorge, which has been closed since April 24.

The agency then announced in July the gorge would be closed indefinitely over fears more material would fall, prompting increased pressure from the public to get a new route sorted as soon as possible.

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Now, the agency is giving the public a say by laying out possible routes online.

DAVID UNWIN/STUFF NZ Transport Agency regional transport systems manager Ross I’Anson.

All of the alternative options can be seen on an online map and digital pins can be placed to leave comments on different parts of the potential routes.

Options include building a stronger route through the gorge through to building a tunnel. The options range from 6km to 19km in length.

Agency regional transport systems manager Ross I'Anson said it was an important step toward finding the best performing option for an alternative route between Manawatū and Hawke's Bay.

DAVID UNWIN/STUFF The Manawatū Gorge was closed indefinitely in June.

"We know how keen people have been to see these options, and we've worked hard with our local partners to get to this point as quickly as possible.

"Receiving feedback from local people and from stakeholders is a vital part of the ongoing process to find a solution for this route."

I'Anson initially tried to shut down questions from the 150-strong crowd, asking instead people approach staff one on one after his presentation.

He was forced to backtrack in the face of outcry from the crowd, who wanted public question and answer time.

Questions then flowed about the likely completion date of the alternative route and when people would be approached about land sales.

I'Anson said there was no definite completion date yet as the route had not been decided, but said the aim was to have it completed within three to four years.

Ashhurst resident Linda Shannon was concerned she would have to sell land to the Government if one of the four alternative options that ran through her section was chosen.

She lives on State Highway 3 and said she wanted an indication of when she was likely to have to give up the land.

I'Anson said it was unclear at this stage.

A shortlist would be made once feedback was received, which would be presented to the public in October, he said. ​

The agency plans to have an alternative route chosen by December.

The Saddle Rd and Pahiatua Track are the current alternative routes to the gorge, but they are windy, narrow and take longer to traverse than the Manawatū Gorge did.

GHD Advisory has been contracted to develop a detailed business case for an alternative route to the Manawatū Gorge.

The contractor is helping evaluate the costs, benefits and viability of various options.

Another meeting will be held at Woodville Sports Stadium, 6pm on Tuesday.

Open days, on October 11 and 12 at the Palmerston North Conference and Function Centre and the Woodville Sports Stadium, will also give people a chance to provide feedback on the options.