It likely won't seem like it to the many of us stuck in holiday gridlocks this summer, but there is a science to traffic jams.

Scientists have just statistical physics to hunt for discernable patterns in six cities, the nearest being Melbourne, in a study that seems to have pin-pointed the moment at which traffic backs up.

The researchers compared individual drivers' travel times and how long it took them to reach their destinations from the beginning of peak hour, with drivers starting their journeys over the next hour of that peak period.

The time it took drivers to reach their destinations was labelled "recovery time".

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One of the team, Dr Meead Saberi of the University of New South Wales, said as recovery time passed the critical threshold where cars using the network outweighed the network's full capacity, traffic started to move beyond congestion to network collapse, or gridlock.

"We have found that this simple "recovery time" measure is directly related to demand and supply - no surprise," Saberi said.

"What is surprising is that all the six cities that we have studied perform similarly."

In other words, despite the various differences between cities in topography, population size, infrastructure, demand and other characteristics particular to each city, transition to gridlock happened in every city in a similar fashion.

The point when this transition happens might be unique to each city, but the researchers now had a quantifiable measure for it.

"The demand over supply ratio that we have measured is the ratio of the vehicle kilometres travelled in a city to the total vehicle distance the road network can support per hour," Saberi said.

"When this ratio exceeds a critical value, we see transition to gridlock. For example, a major global city like London may have a smaller critical value and that's why it sees gridlock more often than, say, a smaller city like Adelaide."

Transport authorities and governments could use the findings to understand when and how traffic forms and how likely it could develop into network collapse.

Monitoring the number of vehicles entering the network and the recovery time could provide an early indication of whether a gridlock is likely to happen or not.

"This information can be used to intervene in the network by managing travel demand or increasing transport supply when and where needed."

A trip to the flicks is good for your soul

Regular visits to the cinema, theatre or to museums could dramatically reduce the chances of becoming depressed in older age. Photo / 123RF
Regular visits to the cinema, theatre or to museums could dramatically reduce the chances of becoming depressed in older age. Photo / 123RF

Regular visits to the cinema, theatre or to museums could dramatically reduce the chances of becoming depressed in older age, a new study has found.

Researchers at University College London found a clear link between the frequency of "cultural engagement" and the chances of someone over 50 developing depression.

It was the first such study to show that cultural activities not only help people manage and recover from depression but can actually help to prevent it.

Their study, which looked at data on more than 2000 people over the age of 50, found people who attended films, plays or exhibitions every few months had a 32 per cent lower risk of developing depression.

Those attending once a month or more had a 48 per cent lower risk.

Now its lead author, Dr Daisy Fancourt, wanted to encourage greater awareness of the benefits so that people can take better control of their own mental health.

"Generally speaking, people know the benefits of eating their five-a-day and of exercise for their physical and mental health, but there is very little awareness that cultural activities also have similar benefits," she said.

"People engage with culture for the pure enjoyment of doing so, but we need to be raising awareness of their wider benefits too."

We lower our voice around people we like

A European study has looked at what happens to the vocal pitch of men and women during speed dating events. Photo / 123RF
A European study has looked at what happens to the vocal pitch of men and women during speed dating events. Photo / 123RF

Humans are known to behave strangely when faced with potential mates, and now a European study has looked at what happens to the vocal pitch of men and women during speed dating events.

In 30 case studies from European events, researchers found women raised their pitch when they met potential mates, but lowered their pitch when they were talking to the men they desired the most or who were "most desired" by other women.

The men, who also lowered their voice around women they liked, were shown to prefer women with deeper voices, suggesting why we change vocal behaviour to attract potential mates.

Scientists recorded the voices of single men and women at a speed dating event and found that women lowered their pitch when talking to men that they personally preferred and were also highly desired by other women in the room.

The study authors say the results support the hypothesis that humans alter the quality of their voices during "real-life mate choice, possibly to signal sexual interest and/or to elicit favourable judgments from potential mates".