Travelling at 60km/h, a two second gap would be a 34m gap between cars. Therefore aiming for a three second gap is better to avoid congestion. Photo / Nick Reed.
Travelling at 60km/h, a two second gap would be a 34m gap between cars. Therefore aiming for a three second gap is better to avoid congestion. Photo / Nick Reed.
A Japanese engineer has boldly claimed he can solve the pain of peak-hour traffic jams by changing the driving habits of just eight motorists.
But many commuters aren't going to like his plan because, counter intuitively, it means you'll have to slow down to get to your destination quicker.
The University of Tokyo's Professor Katsuhiro Nishinari studies the mathematics of traffic jams, a discipline he likes to call "jamology".
Taking inspiration from the constant gap between individual ants, Prof Nishinari said motorists should do the same. Photo / Getty Images
Talking to news.com.au, he said there was one rule that would effectively render traffic jams a thing of the past — and it wasn't just roads. Prof Nishinari said when it came to pedestrian congestion, footpaths should have a dedicated slow lane for the elderly.
Prof Nishinari, who was in Melbourne this month for the Transport and Tourism Forum's Australian Transport Summit, said we could learn a lot from how insects scurry about as "ants never have traffic jams".
That's because ants generally don't brake, and the chain reaction of braking is the problem.
"People are always trying to go fast. When they do, they tend to have less headway between them and the vehicle in front and that is very bad and is where traffic jams occur."
Unlike humans, he said, ants always had a constant headway — or distance — between themselves and the ant in front.
"A jam is a kind of wave in the opposite direction to the direction of travel. Waves is the propagation of braking but if there is headway, the next car does not have to break as much and these waves are dispersed between the cars."
40 metre rule
Taking inspiration from the constant gap between individual ants, Prof Nishinari said motorists should do the same. But not just a small gap — a full 40 metres or more. That's about the length of 10 Holden Barinas.
Travelling at 60km/h, a two second gap would be a 34m gap between cars. Therefore aiming for a three second gap is better to avoid congestion.
Forty metres between cars could get everyone to where they're going faster. Image / news.com.au
You can measure your distance by the amount of time it takes between the car in front passing a fixed object — such as a road sign — and then you reaching it.
The lower the speed, the more time is needed for the minimum 40m gap.
Eight cars
He tested his theory on Tokyo's Shuto Expressway, Japan's busiest motorway.
"At 4pm there was always about a 10km traffic jam. We asked eight cars to keep headway; we asked them to move more slowly than other cars and it was amazing. With just eight cars the jam didn't appear for 40 minutes. If you continuously had all cars (keeping headway) maybe you can shift the onset again and have no traffic jam.
"It's counter intuitive but if we slow down it makes the flow faster. Slower is faster. That's the jamologist's big point."
The chain reaction of braking is the problem. Photo / Dean Purcell
"If you have an upper limit of 100km/h, some people will be doing 90km/h, so drivers will be slowing down to stop bumping into each other and there will be the temptation to change lanes which makes flows less efficient," he said.
"If you have a lower speed you can stop all the shocks in the traffic flow and have a nice smooth flow."
Problem is, we like going fast
It might be a tough ask for drivers who seem to feel the need for speed. On Tuesday, research from NSW Roads and Maritime Services found the majority of drivers in Australia found low-level speeding acceptable.
Men justified speeding because they believed they were safe drivers while women sped because other cars were over the limit around them, reported The Daily Telegraph.
Placing obstacles on stations slows people down but speeds up the overall flow of people. Photo / news.com.au
But if you think leaving 40m between cars is a shift, the jamologist has even more radical ideas to lessen pedestrian congestion.
One solution involves actually putting obstacles in people's paths. Prof Nishinari said it was based on the same theory that going slower sped people up overall.
"For pedestrians, the bottle neck is the problem. On stairs and streets we have traffic jams of people and what I found is if you have obstacles in front of an exit it makes the flow smoother.
"If you're on a train and you put a pole in the middle of the exit then people slow down and that reduces the conflicts between people and the outflow from the train becomes smoother."
Creating obstacles increased the flow of people by 10 per cent.
Pedestrian lanes on footpaths
Prof Nishinari said Melbourne, with its crowded footpaths, had similarities to Tokyo. So a solution he devised for the Japanese capital could work in Victoria.
It would involve splitting footpaths into fast and slow lanes: "The pedestrian flow is currently mixed. I think we should separate lanes with one for bikes, one for young people and another for elderly people."
"A jam is a kind of wave in the opposite direction to the direction of travel." Photo / File
This, he said, would allow each group to "optimise their own path" and would keep the speeds of the various groups consistent, a key factor in stopping delays.
If you've ever been through passport control at Tokyo's busy Narita airport, Prof Nishinari's work has been on display there too.
Queues built up because not enough immigration agents were on. He simply found a way for the authorities to know how many people boarded each flight so they could increase staff at busy periods.
His theories will be tested in the run up to the 2020 Olympic Games, held in Tokyo. He's working with car giant Toyota to see if they can reduce jams in one of the busiest cities during one of its most congested periods.
Until then, the jamologist's advice is to slow down and keep your distance. If just eight of us did that maybe we'd all get to work on time and with less stress.
