Why Freeways come to a stop

Velocitee

Saw this on Digg (I know I know, replace "freeway" with "motorway/ dual carriageway/ road")

http://i40.tinypic.com/ay6d55.png

common sense but if it educates someone I guess it's a good thing.

Senna

The ghost traffic jam, more cars join the stationary cue than are pulling away, so more and more cars are stopped for longer for no reason.

Mingey

Especially when there are only 1-2 lanes most of the time on our motorways

Berty

This is why Jeremy Clarkson does not brake on a motorway. I try not to and use my common sense to anticipate instead of having to brake.

I was driving home from Dublin last night and for no apparent reason a car in another lane of the M7 with nothing in front or behind it braked heavily and then continued. I see this quite a lot during my travels. Tres annoying.

GB15

In the film Mission Impossible 3 Tom Cruise pretends to be a traffic analyst as his job.

He refers to traffic as a living organism where if someone even dabs their brakes the effects can be seen miles back within seconds.

Cookie_Monster

Velocitee wrote: »

http://i40.tinypic.com/ay6d55.png

With gradients like that it's no wonder traffic slows down:D

rgunning

I remember being in a course in college (I did physics) that went through the maths behind this. It is interesting to see the absolute havoc that placing a traffic light in a system like this creates.

You can see how clearing out the lghts on the N4 and N7 has had an effect.

Velocitee wrote: »

Saw this on Digg (I know I know, replace "freeway" with "motorway/ dual carriageway/ road")

http://i40.tinypic.com/ay6d55.png

common sense but if it educates someone I guess it's a good thing.

Saruman

Phantom traffic Jam. Saw this years ago on some tv show. Someone stood on an overpass and watched the traffic and a car at the head of the traffic hit the brakes... This rippled down as each car is forced to apply more pressure until the traffic at the back is either stopped and barely moving.

So the moral of the story is, Brake Tappers should be given the death penalty. We can bring it back just for them.

-Chris-

Berty wrote: »

This is why Jeremy Clarkson does not brake on a motorway. I try not to and use my common sense to anticipate instead of having to brake.

I really frustrate myself when I have to brake on a motorway, I get really annoyed with myself.
I HAAAAAAAATE seeing brakelights on a motorway, it really freaks me out as much as anything else.
I find far more "brakers" in the overtaking lane than the driving lane, I think the kind of people who think it's the fast lane and therefore that's where they should be if they're going fast are the same people who don't leave enough reaction time between themselves and the car in front and end up having to tap their brakes while driving.

Type 17

Play with your own personal traffic jam here (requires Java)

milltown

Velocitee wrote: »

Saw this on Digg (I know I know, replace "freeway" with "motorway/ dual carriageway/ road")

http://i40.tinypic.com/ay6d55.png

common sense but if it educates someone I guess it's a good thing.

At first glance I thought car #3 was driving the wrong way!
Then I realised it's a pickup

Thoie

milltown wrote: »

At first glance I thought car #3 was driving the wrong way!
Then I realised it's a pickup

I had the exact same thought and thought "Well, I'd come to a stop if someone was coming head on at me on a 3 lane road too"

ZYX

It also shows how important it is not to speed when roads are busy. You will just be speeding to the traffic jam. For example this afternoon all the motorways out of Dublin will be busy. There is no point even trying to do 120kph. If everyone relaxed did 90-100kph the traffic would molve much more smoothly and everyone would get home quicker. Of course it will never happen but speed limits should change on motorways depending on how busy they are. Up to say 150kph when very quite, down to say 60kph when really busy and try to keep everything moving smoothly.

jenizzle

AudiChris wrote: »

I really frustrate myself when I have to brake on a motorway, I get really annoyed with myself.
I HAAAAAAAATE seeing brakelights on a motorway, it really freaks me out as much as anything else.
I find far more "brakers" in the overtaking lane than the driving lane, I think the kind of people who think it's the fast lane and therefore that's where they should be if they're going fast are the same people who don't leave enough reaction time between themselves and the car in front and end up having to tap their brakes while driving.

I'm the same. It bugs me when people drive up the ass of the person in front, then they need to jam on the brakes. The person behind them sees the brake lights and does the same for no reason. I make a point of making enough room for myself to slow down without having to hit the brakes too often.

Saruman

ZYX wrote: »

It also shows how important it is not to speed when roads are busy. You will just be speeding to the traffic jam. For example this afternoon all the motorways out of Dublin will be busy. There is no point even trying to do 120kph. If everyone relaxed did 90-100kph the traffic would molve much more smoothly and everyone would get home quicker. Of course it will never happen but speed limits should change on motorways depending on how busy they are. Up to say 150kph when very quite, down to say 60kph when really busy and try to keep everything moving smoothly.

How would that work exactly? Who would determine the speed and how would you determine it and then enforce it?

The same stetch of motorway could have multiple speed limits with this idea.

I do like the 150kph idea on empty motorways though.

cjt156

Saruman wrote: »

How would that work exactly? Who would determine the speed and how would you determine it and then enforce it?

The same stetch of motorway could have multiple speed limits with this idea.

Lots of M'ways in the UK and on the continent have variable speed limits according to weather or traffic conditions. Overhead gantrys with limit signs in LEDs - simple.

seclachi

After driving on irish roads for quite a few years I can say I have only noticed it a few times, generally cos roads over here are generally jammed because of a bottleneck at the end of the motorway, or because there pretty quiet the rest of the time. When it does happen I always assume its because of a car crash or something, and get very confused when the road seems to clear after a few minutes.

aquascrotum

Not sure about other motorways but the M1 north before Balbriggan is ridiculous for phantom jams at commuting hours.

What makes it worse is that when driver is leaving a decent gap to the car in front to "smooth out" the death sentence brake tapper in front, generally you get an impatient ass driving right up yer hole trying to force you to close the gap. All of which is further exacerbated due to the "fast lane" culture, whereby leaving a decent gap when you're in the overtaking lane is criminal because (god forbid) it means someone might pull into the gap you're leaving.

All comes down to one thing - complete lack of driving education and awareness in this country. Take away brakelight backlogs and teach people how to merge at junctions and we could all get up 20mins later in the morning.

craichoe

cjt156 wrote: »

Lots of M'ways in the UK and on the continent have variable speed limits according to weather or traffic conditions. Overhead gantrys with limit signs in LEDs - simple.

Have seen this in Germany, the Speed limit changes depending on the density of the traffic and the weather conditions.

Good idea imo