The report argues politicians must think beyond building new roads and rail lines to tackle Melbourne's growing congestion problem, which delivered a $4.6 billion hit to economic productivity last year. Major projects such as the Metro rail tunnel and level crossing removals are needed, but the 10-year frenzy of construction activity they require threatens to exacerbate that economic hit, unless some of the report's ideas are adopted. Here are three key ideas from the report: Idea 1: Unblock CBD intersections Cars and trucks that block intersections create a ripple effect that slows down traffic right across the CBD.

The institute sampled one week of Google Maps data this month and found average speeds in the Hoddle grid can fall below 13km/h in peak hour. Collins Street is hardest hit, making it Melbourne CBD's slowest street, with average peak-hour speeds as slow as 4.6 km/h when congestion is at its worst on Thursday nights. Motorists who bank up across an intersection are breaking road rule 128. The report argues it's time for traffic police to get much tougher on drivers who break that law. It proposes installing traffic cameras to catch and fine drivers blocking intersections.

However, it acknowledges an awareness campaign would be better in the first instance. Pedestrians are not blameless in blocking busy city intersections either, the institute says. Many cross the street after the green walking cycle has finished and delay right-turning cars from exiting the intersection. Idea 2: CBD airport terminal

People flying out of Melbourne Airport would be able to check-in and clear security at a satellite airport terminal at Southern Cross Station in the CBD, before boarding an express bus to Tullamarine, under this proposal to ease traffic snarls. The concept is similar to Hong Kong's "in-town check-in" service that allows passengers to check-in their luggage in the city centre. The Tullamarine Freeway is being widened at a cost of $1.3 billion, and the Turnbull and Andrews governments have finally agreed that Melbourne Airport needs a rail link, committing a combined $30 million to another study. But any such link would be at least 10 years away from opening, by which time the airport's owners predict the widened freeway will once again start to struggle. The airport had 34 million visitors last year and it's predicted that figure will double in the next 20 years.

Google Maps data indicates some of the worst traffic gridlock is in the last 2 kilometres of the journey from the CBD, where it takes up to 1 minute and 10 seconds to travel just 100 metres. "We are calling for a new satellite terminal to be established at the CBD where domestic passengers could not only check-in for their flight, but pass through security before boarding a secured bus," the report states. The "secured bus" would then take passengers directly from Southern Cross Station to the airport. This innovation would require the co-operation of CityLink owner Transurban, should the buses need an express lane to handle the extra crowds, while the federal government who would have to sign off on security clearances.

Long queues at Melbourne Airport earlier this year. Credit:Penny Stephens Idea 3: 'Uber buses' Melburnians' disdain for bus travel in unrivalled in Australian capital cities. Just 1.4 per cent of the population travel to work by bus, according to 2011 census data. The reasons are many: most come every 30 to 60 minutes, few run after 9pm and some do not run on Sundays; many take indirect routes, and are not given their own lanes or priority at intersections.

Putting bus lanes on arterial roads such as Hoddle Street could attract more passengers. Credit:Angela Wylie But the report argues buses could be made more attractive if: traffic lights were programmed to turn green upon a bus' approach;

more bus priority lanes were installed on arterial roads, and there were;

smaller "on demand" buses for quieter areas. Passengers would book a bus ride online, as they might book a ride with Uber, for example. "In areas or times of the day with low passenger numbers, on-demand booking of buses could be more efficient than some of the circuitous routes that currently occur in suburban areas," the report says.