Motorists who illegally bank up across intersections face a $159 fine.

But drivers flouting Road Rule 128, which involves entering an intersection when it is full and getting stranded there when the lights change, appear to be largely getting away with it.

The breach, which puts the guilty driver, pedestrians and cyclists at risk, attracted an average of just 18 fines a month in 2016-17.

There were 223 fines given out for this road rule breach last financial year. Meanwhile, there were 923,074 infringements for speeding by less than 10km/h and 154,042 red light infringements.

VicRoads' director of journey services, Sameem Moslih, said drivers blocking intersections was a common problem that worsened congestion on Melbourne's roads.

An analysis by VicRoads has revealed the breach commonly occurs at some of Melbourne's most congested corners, including Punt Road and Alexandra Avenue in South Yarra, the West Gate Freeway and Williamstown Road in Yarraville, and the Eastern Freeway and Bullen Road in Kew.

Mr Moslih said just one incident could have knock-on effects across the road network.

"Our whole system is so fine-tuned that even a car blocking an intersection for a few seconds can cause mayhem," he said. "It's unfortunate that where individuals look for a way of easing their own pain, they are causing a great deal of pain for those people in their rearview mirror. It's not everyone who is doing this, people have different pain thresholds and it really goes back to underlying beliefs that people have, and some people believe that their time is more valuable than others', which is unfortunate".

VicRoads is investigating ways to tweak traffic light sequencing at selected intersections to stop the behaviour, he said.

It is targeting four intersections: Dudley Street and Wurundjeri Way in West Melbourne; Keilor Park Drive and Milleara Road in Keilor East; Heaths Road and Morris Road in Hoppers Crossing; and Melbourne Road and The Avenue in Spotswood.

Ben Rossiter, executive officer at Victoria Walks, a pedestrian advocacy group, said vehicles that blocked pedestrian crossings posed a serious safety risk, particularly to elderly walkers, those with a disability and people with prams and young children.

Analysis of road crash statistics shows that 45 per cent of all crashes involving older pedestrians occur at intersections and 21 per cent are at intersections that have traffic signals. This shows vulnerable pedestrians are frequently hit in locations where they should be safe, Dr Rossiter said.

"I can't think of any intersection, even in the CBD, where I've ever seen this road rule being enforced. I've never seen it," he said.

Think tank the McKell Institute, which used Google Maps data to analyse causes and possible solutions for congestion in the Hoddle Grid, recommended tougher policing of intersection blockers.

The institute found that road rule breaches riddling CBD intersections were also being committed by pedestrians (albeit, to a lesser extent than motorists) who try to cross the road during a flashing red walking cycle, delaying left-turning vehicles.