Work to restrict vehicle access to the summit of Auckland's iconic Maungakiekie (One Tree Hill) has begun.

Work to reconfigure its main road started today in a bid to tighten safety measures and help conserve the maunga as a wāhi tapu.

Yesterday the work to pedestrianize the summit of One Tree Hill kicked off and the Tūpuna Maunga Authority's operations manager Nick Turoa says it’ll take four to six weeks to complete the route safer for pedestrians and cyclists.

“Kia manaakihia ngā tangata e hīkoi haere ki runga ki te tihi, he mōrearea rawa atu ngā waka e piki ake ki runga rā.”

One Tree Hill has national significance for many reasons such as the famous hit 'U2' filmed in 1987, right through to the time activist Mike Smith chopped the pine tree down in 1999.

But Turoa says today is all about recognising the maunga's ancestral purpose.

“To build distinct entrance ways such as waharoa and alike so we can explain to the public that this is isn’t just a park, it’s actually a maunga - an ancestor of ngā mana whenua o Tāmaki Makaurau.”

This is the fourth of six maunga tīpuna around Auckland to become pedestrian-only spaces but despite that, vehicle access will still be maintained for people with limited mobility.

Once construction is complete the summit will permanently be closed to all vehicles. While a date is yet to be finalised, the notice will go out one week before it closes permanently.