Collins St is a major traffic chokepoint in the CBD, with a projected speed as low as 4.6kmh in congested traffic.
Recent research by McKell Institute shows during extreme congestion on Collins St, it would take as long as 1 minute, 18 seconds to drive just 100 metres.
Across the Hoddle Grid, the average speed in normal traffic is between 13 and 23kmh and congested traffic speed is from 7-22kmh.
McKell Institute says the wide variability in traffic flow is often caused by co-ordination failure, not just an increased number of cars.
McKells says Melbourne’s traffic congestion is costing the city $4.6 billion each year and is estimated to rise to $7-10 billion by 2030.
It suggests that strict compliance with the State Government Road Safety Road Rule’s Regulation 128 could ease the congestion.
McKell is also calling for an airport terminal to be built in the CBD, where a secured bus could drop off passengers “airside”.
The organisation says this could alleviate congestion in “one of the city’s most notorious routes” from the CBD to the Tullamarine Airport.