The association launched traffic-mapping technology on its site 18 months ago. Routes marked in black show where traffic is moving at under 25 per cent of the speed limit. "I have never seen so much black in the CBD. I've never seen anything like this."
Mr Allen said rubberneckers slowing down to look at the crash were the root of the problem.
"No question - once you have a serious incident with rubberneckers on one side and everybody else on the other side, that's what's causing the problem."
Auckland Transport spokeswoman Sharon Hunter confirmed the one crash on the Southern Motorway caused the gridlock. She estimated the crash caused a delay of two hours or more.
Mayor Len Brown said the gridlock showed "why we need to invest in an integrated transport system including trains, ferries and buses".
"Only through initiatives such as integrated ticketing, our new electric train fleet and the City Rail Link, can we unclog our roads and unlock the potential of Auckland."
Auckland Councillor Cameron Brewer said he had to miss the Orakei Local Board meeting because of the traffic. He left the Town Hall at 5pm, spent 40 minutes on Hobson St, opted to take the Northwestern Motorway, got off at St Lukes and made his way across town to his home in Ellerslie, arriving an hour and 45 minutes later.
"When the airport western ring road to Waterview is complete that will take some pressure off SH1, but what that one accident shows is just how reliant almost all of us are on cars, and that's not going to change much in the foreseeable future.
"It should be a real wake-up call to the mayor as to where the real problems and frustrations lie for most Aucklanders - that is in traffic jams."
Mr Brewer said he'd like more improvements to the motorway network and more bus lanes, ferry terminals and cycle and walkways, rather than the CBD rail tunnel.
After the crash, between Mountain and Market Rds, the Southern Motorway was reduced to just one lane as emergency services worked to cut the van driver from his vehicle and clear the wreckage. The man was taken to Auckland City Hospital in a serious condition.
By 4.15pm, traffic was at a standstill at Spaghetti Junction, which links the motorways as well as exits to the city and port. Police urged motorists to avoid the area or delay their travel.
But two hours later, a line of buses half a kilometre long still stretched up Albert St, and cars were travelling about 5km/h on the motorways. Traffic on Queen St, Ponsonby Rd, Symonds St, Albert St and Karangahape Rd was barely moving.
Jennifer Lann said she boarded a bus heading west that left the Britomart at 5.35pm and was only halfway up Albert St by 6.15pm, so she ran back to the station and caught a train.
Tip-off at the Breakers-Taipans basketball match at the North Shore Events Centre at 7.30pm was delayed 10 minutes because of the gridlock.
One fan said organisers were forced to delay the start because there was so few people at the stadium.
Last year, transport engineers Sinclair Knight Merz warned that traffic speed in central Auckland would halve in the morning peak to 8km/h by 2021 if the rail tunnel wasn't built.
