An extension of the popular Hauraki Rail Trail cycleway is expected to boost tourism in the area.

Resource consent has been lodged for a new 56 kilometre coastal route from Kopu to Kaiaua.

It'll cost around $4 million.

Thames Coromandel Regional Council Area Manager Greg Hampton says it's an exciting development.

"Lengthening the trail network makes it a more multi day experience, it'll create bigger numbers and better benefits all round."

Hampton says it's a lovely coastal route that stops off at Miranda Hot Springs.

"This stage actually takes the rail trail close to Auckland, which is a great benefit.

"A bit closer to Auckland, so hopefully more people start to utilise it."