IT was the car that stopped a city. With a client sitting in the back seat of the luxury, all-leather interior Audi A8, a Sydney chauffeur was stunned when his vehicle - worth more than $200,000 - suddenly came to a stop heading south in peak-hour traffic on the Eastern Distributor on-ramp at Darlinghurst.

Two hours and two towtrucks later the city was crippled: millions of dollars in lost productivity and a traffic jam stretching up to 15km long.

Sydney Business Chamber executive director Patricia Forsythe wouldn't put a precise value on yesterday's gridlock but said the incident highlighted how congestion cost the city billions of dollars in lost productivity every year.

"An important element of productivity is being able to move people and freight around a city as efficiently and cost-effectively as possible - an efficient and responsive transport network is critical to a productive and successful city," she said.

"Traffic disruptions have a cost on business. Congestion costs on Sydney have been estimated to be several billion dollars every year and that figure is rising."

Last night the chauffeur company's boss apologised to drivers, but said he too was baffled why it took so long for the Audi to be moved.

"Any incident on a road that creates problems for the travelling public is an issue, but that is something we didn't have any control over," Hornsby-based luxury chauffeur service Brunel Worldwide chief executive Paul Highams said last night.

"We had a mechanical breakdown in the vehicle. We don't like it any more than you do. I was caught in the traffic too, just like everyone else."After breaking down at 7am, the driver called Audi's roadside assistance claiming the vehicle's electrics were dead, his handbrake stuck and the key jammed in the ignition. He was told his warranty was out of date. Having declined to renew his warranty, he called the NRMA - only to be told the group didn't have access to the tunnel.

The state government's Traffic Management Centre was already looking at the vehicle on CCTV and when a towtruck operated by Eastern Distributor Motorway appeared its winch was not strong enough to drag the vehicle on to the tray.

"It was chaos," Australian Traffic Network operations manager Ian Wallace said. "You only had one lane blocked, but there were drivers merging from three different directions."

The traffic stretched to Epping Rd in North Ryde, the Pacific Highway at Killara, and across the Spit Bridge.

Timeline to chaos:

7am: Chauffeur-driven Audi A8L worth $200,000+ breaks down on Eastern Distributor, Darlinghurst,

near the Bourke St on-ramp heading southbound

7.10am: One of four southbound lanes is blocked, and traffic immediately starts to build up

7.15am: Driver calls Audi roadside assistance, but is told his warranty is out of date. Declines an offer to renew his account

7.15am: Driver calls NRMA Roadside Assistance for help. Told NRMA is not allowed access to the tunnel, so organises for passenger to be picked up by another chauffeur

7.25am: Eastern Distributor Motorway tow truck crew arrives. Audi’s electrical system has shut down, so brake and steering systems not working. Wheels are locked. Crew tries to tow vehicle, but truck winch is not strong enough to drag vehicle on to tray

7.40am: Sydney Harbour Bridge tow truck crew called to remove vehicle. Tow truck was completing another incident and travelled to the ED as soon as it was cleared, but traffic delayed its arrival. Traffic queue is now back to Gore Hill Freeway and Military Road, Neutral Bay

8.20am: Tow truck arrives and manoeuvres the vehicle on to the back of the tilt tray

8.40am: Separate breakdown occurs at the same location, just behind original breakdown

8.45am: First incident is cleared. Vehicle taken to Audi Centre at Zetland. Traffic backed up 10km to the Lane Cove Tunnel, to the Pacific Highway at Chatswood and on Military Road, Mosman

8.50am: Second incident is cleared by ED tow truck, but traffic is now banked up 15km to Epping Road, North Ryde, the Pacific Highway at Killara, and across the Spit Bridge to Manly Road, Seaforth

10.30am: Traffic gridlock eases

11am: Roads finally clear

Originally published as Audi manage to stall the traffic?