Police in Wellington are awaiting blood test results taken under the newly introduced Compulsory Impairment Test for a driver seen colliding with several motorway barriers and endangering other motorists.

Police Communications received numerous calls from members of the public about a red car travelling up Aotea onramp to the Wellington Urban Motorway on Friday 19 March 2010 at about 6.50pm.

Police Highway Patrol Senior Constable Bruce Pauling attended the incident and praised several members of the public for containing the vehicle and 43 year old driver when she stopped suddenly north of Johnsonville.

"The driver's blatant disregard for the safety of other motorists is appalling," Senior Constable Pauling says. "Her apparent decision to drive after consuming excessive amounts of alcohol or drugs put herself and other motorists at great risk."

"The outstanding actions of the public prevented this person from continuing to drive and likely causing a senseless fatality."

The car first attracted attention after being seen colliding with a concrete barrier on the Aotea onramp before reversing slightly and continuing onto the motorway. It continually weaved across three lanes of motorway traffic and collided several times with median barriers and side railings through Ngauranga Gorge.