Phantom traffic jams
Discussion
I was wondering if one of the reasons we have these is because of manual and auto boxes?
If you have a car with a manual box and the driver eases of the throttle it will slow quicker than an auto, because of friction (manuals have gears and are directly connected to the drive wheels but auto's are fluid based) so the auto car will have to brake therefore creating a ripple effect.
I think the amount of manuals must be at least 70%?
What do you reckon ph massive?
If you have a car with a manual box and the driver eases of the throttle it will slow quicker than an auto, because of friction (manuals have gears and are directly connected to the drive wheels but auto's are fluid based) so the auto car will have to brake therefore creating a ripple effect.
I think the amount of manuals must be at least 70%?
What do you reckon ph massive?
No.
Even the RAC know what it is:
Even the RAC know what it is:
RAC said:
Phantom Jam
The cost of congestion on the UK’s roads could double to £30 billion in the next ten years* but the mystery traffic jams which contribute to it could be avoided, claimed the RAC Foundation today (10).
Most drivers will recognise the scenario – you are making steady progress along the motorway when suddenly you come to a sudden halt at the tail end of a lengthy queue of traffic. When you move off again you look for the cause of the jam, but there isn’t one. No accident damaged cars, no breakdown, no dead animal, and no debris strewn on the road. So what caused everyone to stop?
The answer is simple according to the Foundation - drivers travelling too close to the car in front.
So called "phantom traffic jams" are actually caused by a vehicle braking sharply - causing a red light domino effect. The red light is the brake light that the following driver sees ahead. The driver behind then brakes suddenly and this has a domino effect until further down the line traffic grinds to a halt.
Motorists are then perplexed as to what has caused the traffic jam. In reality they have all caused the traffic jam because of their sharp braking.
While compiling data for a survey on tailgating recently at locations all over the UK, RAC Foundation staff witnessed many of these "phantom" traffic jams and were able to identify the top five causes.
1. Tailgaters: The number one cause of phantom traffic jams is indeed motorists themselves who tailgate. If a vehicle is driving too close to the vehicle in front and the lead vehicle slows down then the following vehicle will have to brake sharply. So the easiest way to prevent phantom traffic jams is to keep a good distance from the car ahead.
2. Slow coach: The number two cause is the slow coach. This can be any vehicle that pulls into the outside lane at a speed much slower than the general flow of traffic. It can be a coach or truck, particularly on a two-lane motorway or dual carriageway, but it is equally likely to be a car driver wearing a flat cap.
3. The cop: Yes, sometimes the police can trigger phantom jams. The lead car in the outside lane spots a police car on the hard shoulder or inside lane and brakes suddenly.
4. The camera: This happens most often where speed cameras are obscured by a dual carriageway underpass. The lead car spots the Gatos (or indeed CCTV or traffic master camera and not a speed camera) and brakes suddenly. The dominos begin to role.
5. The rubbernecker: This problem occurs when there has been an accident on the opposite carriageway and the rubberneckers brake hard to have a good look. This causes massive tailbacks and even when the accident is cleared away delays can still occur and hence the phantom traffic jam.
The cost of congestion on the UK’s roads could double to £30 billion in the next ten years* but the mystery traffic jams which contribute to it could be avoided, claimed the RAC Foundation today (10).
Most drivers will recognise the scenario – you are making steady progress along the motorway when suddenly you come to a sudden halt at the tail end of a lengthy queue of traffic. When you move off again you look for the cause of the jam, but there isn’t one. No accident damaged cars, no breakdown, no dead animal, and no debris strewn on the road. So what caused everyone to stop?
The answer is simple according to the Foundation - drivers travelling too close to the car in front.
So called "phantom traffic jams" are actually caused by a vehicle braking sharply - causing a red light domino effect. The red light is the brake light that the following driver sees ahead. The driver behind then brakes suddenly and this has a domino effect until further down the line traffic grinds to a halt.
Motorists are then perplexed as to what has caused the traffic jam. In reality they have all caused the traffic jam because of their sharp braking.
While compiling data for a survey on tailgating recently at locations all over the UK, RAC Foundation staff witnessed many of these "phantom" traffic jams and were able to identify the top five causes.
1. Tailgaters: The number one cause of phantom traffic jams is indeed motorists themselves who tailgate. If a vehicle is driving too close to the vehicle in front and the lead vehicle slows down then the following vehicle will have to brake sharply. So the easiest way to prevent phantom traffic jams is to keep a good distance from the car ahead.
2. Slow coach: The number two cause is the slow coach. This can be any vehicle that pulls into the outside lane at a speed much slower than the general flow of traffic. It can be a coach or truck, particularly on a two-lane motorway or dual carriageway, but it is equally likely to be a car driver wearing a flat cap.
3. The cop: Yes, sometimes the police can trigger phantom jams. The lead car in the outside lane spots a police car on the hard shoulder or inside lane and brakes suddenly.
4. The camera: This happens most often where speed cameras are obscured by a dual carriageway underpass. The lead car spots the Gatos (or indeed CCTV or traffic master camera and not a speed camera) and brakes suddenly. The dominos begin to role.
5. The rubbernecker: This problem occurs when there has been an accident on the opposite carriageway and the rubberneckers brake hard to have a good look. This causes massive tailbacks and even when the accident is cleared away delays can still occur and hence the phantom traffic jam.
tting himself. I've been saying this for years, you go to somewhere like the US where every car is an auto and it doesnt happen, Everyone knows that brakelights dont mean the car in front is braking heavily so they dont do the same. Over here the first hint of a brake light coming on and everyone behind is jumping on their brakes as hard as possible causing phantom traffic jams, accidents etc etc
Nickyboy said:
I've been saying this for years, you go to somewhere like the US where every car is an auto and it doesnt happen, Everyone knows that brakelights dont mean the car in front is braking heavily so they dont do the same. Over here the first hint of a brake light coming on and everyone behind is jumping on their brakes as hard as possible causing phantom traffic jams, accidents etc etc
They also drive slower, less aggressively, and can overtake in any lane. 
I try my best to leave a decent gap and use some of it up rather than braking to ease out the flow behind me, because unlike the "2 ft off your arse" numpties I understand fluid dynamics.
There's a good demonstration video (from a Japanese university I think) of cars driving round in a circle to show what causes congestion. Youtube and Google searches for the obvious terms haven't uncovered it though.
There's a good demonstration video (from a Japanese university I think) of cars driving round in a circle to show what causes congestion. Youtube and Google searches for the obvious terms haven't uncovered it though.
Ayahuasca said:
Nickyboy said:
I've been saying this for years, you go to somewhere like the US where every car is an auto and it doesnt happen, Everyone knows that brakelights dont mean the car in front is braking heavily so they dont do the same. Over here the first hint of a brake light coming on and everyone behind is jumping on their brakes as hard as possible causing phantom traffic jams, accidents etc etc
They also drive slower, less aggressively, and can overtake in any lane. 
eta On topic, I agree it's all to do with following distances. In stop and go traffic, I'm one of those who lets a good space open up between me and the car ahead to save clutching in and out again and again...baffles me why people sit right up each other's arses treading on the brakes all the time
Edited by collateral on Wednesday 29th July 00:45
Since switching to a car with a turbo I leave a bigger gap now. Car infront accelerates away, you accelerate to match.....woahhh turbo cuts in you're flying right up towards his 4ss and warp factor 10, you have to brake. It's taken a while to modify my driving style/habit to try and prevent that.
Another reason is that a rolling road block is being performed by the police or ourselves. The traffic speed is reduced under control to clear whatever needs to be cleared and the queue starts to build up. Once the obstruction is cleared and the traffic starts moving, by the time they get to the site of the obstruction, everyone has gone.
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