@Mame,
Quote:When I moved to West Vancouver and had to cross the Lions Gate Bridge I noticed a phenomenon I've never had explained to me satisfactorily.
You get to the the causeway and there's at least a 5 min bottleneck, often more. But once you get ON the bridge, you can see there's nobody ahead for blocks and blocks. Where did all the bottlenecked cars go?
How does this happen or why
As a former traffic helicopter co-pilot, I feel qualified to answer that one.
Heavy traffic moves much like a caterpillar. Imagine an entire string of cars like toy cars connected with a little rubber bands. Pull on the front car and it moves a couple inches before moving the second car, and likewise on down the line. A moving line of cars is 3 times longer than a stopped line of cars.
So, in moving traffic, something causes a bottle neck. An entrance to a bridge, a tunnel, someone touches their brakes which causes the car behind them to slow down, a cardboard box in the road... whatever. It starts the caterpillar effect. Cars back up before the restriction, then spread out after it.
When on car taps its brakes, the car behind slows down, which causes the car behind THAT car to slow down. I've seen it thousands of times from above. One person taps their brakes in moving rush hour traffic, its enough to cause a bottleneck right there for the next hour. You've described the same thing; you're driving along in stop and go, then for no reason, traffic just starts moving at a certain point. That's why.
Here's the bottom line and there is no getting around this because its fact. Scientists, mathematicians, and statisticians have known this since the 40s and it is undisputable. Maporsche, Setanta, and others on the "slow-down" bandwagon are making incorrect assumptions based on their own vigilante ignorance. OccomBill has the best grasp on this topic so far.
Moving traffic uses the hourglass principle. If every grain of sand were identical, it wouldn't work. They would find a way to clog up the hole in the hourglass. Every grain of sand is different, and therefore they move at different speeds, different patterns, and different success rates.
To say that there is one magic safe speed is just hilarious. How about the 18-year old girl breaking up with her boyfriend on the cell phone in the left lane in daddy's new SUV that she's only driven twice? Compare that with the focused 40-year old in a 2007 Camry in the next lane, and the 80-year old in a 1965 pickup with manual drum brakes and bad ball joints. Do you really think they are all capable of safely travelling the same speed? And what gives you the right to enforce the law?
You are confusing legality with morality. Its not your right to tell me how to drive. If the law enforcement agency wants to disagree, they can write me a ticket. You, on the other hand, do not have the right to clog traffic, prevent me from getting to the hospital when my wife is in labor, or tell me to slow down. Not only do you not have the right, ITS ILLEGAL IN 39 STATES. It is illegal to travel in the left lane UNLESS you are passing a vehicle. That means you must be actively engaged in going faster than another vehicle in the lane to your right, and then you have the LEGAL OBLIGATION to clear the left lane once you have put a safe distance between you and the vehicle you passed. Its the law. Another thing you don't realize is that ITS ILLEGAL TO PASS ON THE RIGHT in most states, so when you refuse to get your fat-ass SUV out of the left lane because you're talking to Gladys about her meatloaf recipe on the cell phone, you are forcing me to pass on the right and simply break another law.
So, while I'm participating in safely driving 65 in a 65, and you're in the left lane doing 63 for no reason and you see me come up behind you, consider that the LAW is on my side, YOU are breaking the law, and you are congesting traffic and possibly creating accident hazzards.
Slow doesn't prevent accidents. The way to prevent accidents is to drive so that you don't ever cause another driver to have to alter their driving. Don't merge into a lane if it would cause the driver behind you to slow down. Don't change lanes unless you have to. DON'T DRIVE IN THE LEFT LANE. Of course the traffic pattern has to change for wildlife in the road, stop lights, weather, etc, but if the traffic pattern never changed... if you never caused anyone to change their speed or alter their course and if everyone else did the same, there would be no traffic collisions.
That is fact, it has been tested, proven, and reproven over 70 years of traffic study, and its why those 39 states have made it illegal to travel in the left lane. It shocks me how little people remember from their driver training and testing. That fact is IN THE DRIVER'S MANUAL of almost every state. For Maporsche and Setanta to argue to the contrary is pretty laughable.