A senior fire officer has praised members of the public who rallied to help at the scene of a fatal Dunedin crash yesterday, before emergency services arrived.

Fire and Emergency New Zealand Senior Station Officer Mark Leonard said several members of the public had provided "some really good assistance before emergency services arrived'', including by providing initial first aid for the person in the vehicle.

Other members of the public had also worked to try to stabilise the crashed vehicle to stop it from tipping over, Mr Leonard said.

A motorist died after a late model Nissan Leaf electric car hit a pole near the top of Stuart St, Dunedin, yesterday evening.

Alerted at 5.20pm, firefighters from the Rosyln and Willowbank fire stations attended and began urgent first aid treatment of the injured driver.

The crash happened on the inside lane of the uphill section of the street, about 100m below the Roslyn overbridge.

A smashed Kaikorai Valley traffic sign was lying on the footpath beside the lighting pole which had apparently been struck by the car.

Police last night confirmed the motorist's death and said the police serious crash unit was investigating the cause of the crash.

After most other officers had left, an officer with a light on his helmet, and a supported by a police wagon, continued a more detailed study of the cordoned-off scene.

Mr Leonard said the Willowbank fire rescue tender had earlier been placed close to the car, to stabilise the vehicle "so it didn't roll'' and prevent it from moving, while rescuers helped the injured person inside, Mr Leonard said.

It is understood the motorist was a man.

"Further information regarding the deceased will not be released until next of kin notifications have taken place,'' a police spokesman said.

Leonard said firefighters were able to remove the injured person without having to use jaws of life cutting gear, and a firefighter had also accompanied the injured person to Dunedin Hospital via ambulance to further help with care.

It had initially been difficult to approach the accident scene because of "quite heavy'' traffic in the area, but the Willowbank rescue tender was able to arrive by driving on the wrong side of Stuart St, he said.

Police, St John Ambulance and firefighters had co-operated well in a bid to save the motorist, he said.

One nearby resident went out to investigate after hearing "a loud bang''.

Another resident in the area also "heard a bang and some screeching [of metal or tyres]''.

"I didn't think it was anything, but then I heard the sirens after that,'' he said.

In the immediate aftermath of the crash, the two uphill lanes of Stuart St were cordoned off by police, between the Moana Pool area and the top of the street.

At least three police cars with flashing lights blocked off key entry points, and three more police vehicles were at the immediate crash scene.