Motorway "Active traffic management"??

steveandel

I think you'll find it does work in most cases actually. Having travelled through it at 50 you don't know how bad it could have been if everyone was going through at 70!!
The idea is to reduce the speed to keep the flow steady. When a road is heavily congested, a reduced speed helps to maintain the rate of progress whereas a faster speed leads to much more stop/start or phantom queues just due to the number of cars on that section of road. By using ATM the flow is kept steady and journey time reliability is higher
There are all sorts of studies on the theory if you wish to read up on them. Most of it is based around transition theory.

casper_g

I remember a maths lesson once where we worked out that if people actually observed the stopping distances in the highway code the optimum speed for maximising the throughput of vehicles would be something ridiculously low -- 15 mph rings a bell but don't quote me.

On the M42 when it's at its busiest I find the hard shoulder a great place to be, even if it is for the next exit only. Driving up the exits, round the roundabouts and back on again is sometimes the quickest part!

Keith

The M1 at 6-10 has this fitted, the cameras are yet to be installed, the reason the traffic is slowed is to reduce pollution!

flyingscotno1

goldspanners wrote: »

im sure it will help for a while,it might even reduce congestion on london road.
i think where it ends is a bit of a joke and will be a huge bottle neck, it merges onto the M8 at the end of the kingston bridge,why? who had that idea? lets build a road to ease congestion,where shall we make it end? how does the busiest bridge in scotland sound? ideal!
it should be taken to the M77 junction with no city centre access,a M8 bypass if you like, use the M8 for the city,use the M74 for any other route past the city centre.

it only has to work for a year or 2 for me anyway.

It uses the outer carriageways of the M77, it is basically using the old M74 alignment built years ago. There is no Kingston Bridge Access.

Lum

neilmcl wrote: »

I know how they work but what I'm saying is they haven't been active below 70mph since day one.

Also to pick up on another point you made, there isn't cameras behind every sign, you can tell where the cameras are by looking at the oncoming lane opposite, if there are cameras on that gantry there'll be ones on yours as well.

This is correct, however technically you can only tell if there is a "camera housing" using this method.

I'm told that only two of the gantries actually have cameras in the camera housings and that for health&safety reasons they'd have to close that stretch of motorway in it's entirity in order to move or add cameras.

No I don't know which two gantries they are.

goldspanners

flyingscotno1 wrote: »

It uses the outer carriageways of the M77, it is basically using the old M74 alignment built years ago. There is no Kingston Bridge Access.

thank god for that. i havent had a look at any plans for it, i was just assuming where it might end by the bridges that have been going up.

globalds

If you have driven down the M6 recently and seen all the road works ,then you may be aware that the next big section of motorway to be actively managed is between J10a and J8 ..This is the section that tends to be very busy in mornings going into Birmingham from the North.
http://www.highways.gov.uk/knowledge/1356.aspx
The people who tend to moan about active traffic management are generally the ones who are not heavy users of the section of road.
It is used as a last resort because the area of road is not working.

exup

casper_g wrote: »

I remember a maths lesson once where we worked out that if people actually observed the stopping distances in the highway code the optimum speed for maximising the throughput of vehicles would be something ridiculously low -- 15 mph rings a bell but don't quote me.

On the M42 when it's at its busiest I find the hard shoulder a great place to be, even if it is for the next exit only. Driving up the exits, round the roundabouts and back on again is sometimes the quickest part!

55mph is supposed to tbe the optimum speed - oops sorry I quoted you

Barneysmom

Not all the gantrys have cameras, my satnav picks them out. But no point trying to speed anyway in the mornings, it's just too heavy, they'll never solve the traffic problem.

casper_g

exup wrote: »

55mph is supposed to tbe the optimum speed - oops sorry I quoted you

Hmm, if that's right it fits in with the fact that speed limits on the "Active Traffic Management" motorways seem to vary between 50-60 mph much of the time.