Friday 1st September 2006

Slip road signals arrive

More congestion-cutting schemes

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On-ramp signals in Florida, USA

Another congestion relief scheme includes traffic lights on motorway slip roads -- which have been shown to work abroad.

This one starts in west and south Yorkshire this week.

Part of a national £6 million project, the scheme will also help to improve safety on the region's motorways, according to the Highways Agency.

Motorway access management, consisting of traffic lights on motorway entry slip roads, is being installed initially at seven locations on the M62 and M1 in west and south Yorkshire to manage the flow of traffic joining motorways. The signals help traffic to filter safely and smoothly on to the motorway without causing unnecessary hold-ups to motorway traffic.

The system is being used overseas in the Netherlands and the US and recently went live on a number of motorway sites in the north-west. It was successfully tested on the M6 north of Birmingham, where it reduced congestion and improved journey times by up to 11 per cent.

"This is just one of the innovative techniques being introduced by the Highways Agency to deal with congestion and improve journey time reliability," said Roger Wantling, project manager for the Agency.

"Around peak times, congestion often occurs near junctions because vehicles are attempting to join the motorway while there is already heavy traffic on the motorway causing 'stop start' driving conditions.

"By introducing traffic lights on entry slip roads, we aim to smooth out the flow of traffic on the motorway."

The sites affected in west and south Yorkshire are the M62 Junction 25, M1 Junction 41, M1 Junction 40, M1 Junction 39, M1 Junction 35a, M1 Junction 35 and M1 Junction 33.

Work to install the new traffic signals begins on Wednesday August 30th and is expected to be completed by the end of October, when the lights will be introduced in a phased programme.

Motorway access management works using sensors located on the carriageway to monitor traffic flow. Additional sensors on the slip road automatically turn off the system to prevent the build up of traffic on the local road network.

Installation work for the new system will take place overnight and at off-peak times during the day.

One comment on a US blog, which welcomed the arrival of such signals, said:

This system may work in the genteel midwest: I saw it years ago on the interstates feeding into Minneapolis-St Paul; thoughtful patient little people sitting quietly and obediently, clean white hands on the wheel, bland, serious expressions, etc.

But nobody with a pair of brain cells to rub together thinks it can work in south Florida. I predict fights, shootings, dueling serenades of car horns (and maybe shivs) as maddened, foaming drivers stew in their cars for whole minutes on end at the cusp of the interstate.

This is duckshit: somebody other than the roadworkers union has earned himself a kickback. Great. The rest of us lose. Again.

^{Photo by Alesh Houdek}

[chris_crossley]

Sorry, i'm being thick here.

Does it mean that your not allowed on the motorway untill it detects a gap?
On roads into leeds you might as well just give up on a morning. There are no gaps.
The only way onto the road is push in.

The other option which i use are back roads to avoid the motor way completely.
Is it just a way of getting us to stop on the entrace to a motorway. Than all they need to do is add a toll booth!

Arrrrghghghrghrgrhgr

[hahithestevieboy]

What a crock of s**te. more rubbish policy making. more excuses to get a congestion charge of some kind. Do they even turn off the traffic lights in the middle of the night or will you have to sit there for 5 minutes (like a bus riding fool) and wait to get on to an empty motorway? And the lights will go green when there is too much traffic on the slip road? Doesnt make sense. Flawed logic as always. Makes me thing that they've got a load of car hating monkeys (on a chain) sitting there, thinking of ways to waste my tax money on stuff i didnt ask for and that will make my life worse not better. useless bunch of pr1cks.

[langy]

I thought this was instaled on the M27 years ago. It used to be known as 'Ramp Metering' see here if you are really bored www.highways.gov.uk/knowledge/8877.aspx

[fidgits]

Having driven a lot in California, where they have these systems active in rush hour - it does actually work.

They tend to let a one car go per green light, and it changes every couple of seconds or so.

While you do get a queue on the slip road - generally you only have a minute's wait in worst case - which to be honest you can get with the system today.

Depending on how they implement it - its probably a good idea...

[Timberwolf]

The two problems I most commonly see with merging on to the motorway:

Aggressive driver comes thundering down the slip road on maximum attack, is up to 90 at the merging point... and hasn't looked to see if there's a gap at any point in the proceedings. As long as luck doesn't run out, they slam through a marginal gap forcing motorists around them to brake, swerve and scatter, before blasting out into the overtaking lane with headlamps flashing.

Dithering Doris - or male equivalent - comes trundling down the slip road at fourty miles per hour. When they check their mirrors, they see a car several hundred yards behind on the motorway. Worried about colliding, they slow down to thirty to let the car past... but then there's another one behind that, and the process can continue up to the point where they come to a miserable halt on the hard shoulder at the end of the slip road.

So how does this solution deal with either of the above?

Edited by Timberwolf on Friday 1st September 14:10

[jon-]

Everyone is looking at this from the people joining the motorways view so i can only assume no one does that much motorway driving.

I'd happily wait 5 minutes to join the m25 if it meant i didn't crawl past every major junction.

[tony*t3]

They tried this on the M27 some years ago, then the lights dissapeared. Useless. They changed from red/green/red and over again sooo quickly I just ignored them and drove straight through - by the time you started slowing down for the red, they had turned green, and if you werent quick, they were red again. So everyone just drove through them whatwever the colour, apart from a few old ladies that stopped and then werent quick enough to get going again when they cycled green back to red again, causing near catastrophy for approaching cars....

Edited by tony*t3 on Friday 1st September 14:15

[heavybear]

Errr... this looks wierd. Isn't this the same scheme as the trial that failed expensively on the M27 over the past few years and has been discontinued???

[Slowlane]

chris_crossley said:

Sorry, i'm being thick here.

Does it mean that your not allowed on the motorway untill it detects a gap?
On roads into leeds you might as well just give up on a morning. There are no gaps.
The only way onto the road is push in.

The other option which i use are back roads to avoid the motor way completely.
Is it just a way of getting us to stop on the entrace to a motorway. Than all they need to do is add a toll booth!

Arrrrghghghrghrgrhgr

Back roads not for long after hey get a 20mph sorted

[Dr S]

It would be so simple: Teach drivers to a) accelerate on the slip lane to match speed of the oncoming traffic and b) that they don't have right of way into the motorway - "deskilling" is the word again...

[davy9449]

"But nobody with a pair of brain cells to rub together thinks it can work in south Florida. I predict fights, shootings, dueling serenades of car horns (and maybe shivs) as maddened, foaming drivers stew in their cars for whole minutes on end at the cusp of the interstate"

You can always rely on the yanks to sum elequently!!

For the record, anything that helps heavy congestion near filters is fine by me.... although the scheme is a little porous!!

[LooseCannon]

I'm for anything that stops these arrogant arsholes who surf through junctions to miss the holdups being created by selfish tts just like themselves just minutes earlier.....

[Marshy]

Another vote for here. Works in California in the Valley: two lanes of traffic on the slip road, and each lane goes alternately green for a couple of seconds, really smooths out the traffic flow at the small expense of queuing for a few mins on the slip road.

[davidy]

It is indeed known as Ramp Metering

This has been in use on the M6 at Birmingham near Walsall for nearly 20 years. I was involved in the original software implementation (hopefully re-written by now!!!) and our data reports indicated that it increased the average speed on the Motorway between those junctions from 17mph to 35mph during peak hours.

Unfortunately in the last 20 years the number of vehicles on UK roads has increased by 50% and I suspect that now the system is overloaded.

Also the manadatory signlimits on the M25/M42 work as well as if vehicles travel slower then you get a bigger vehicale occupancy of the road, as the inter-vehicle gaps are reduced, thus enabling a road to have more vehicles on it. If everyone slowed down very gradually and speed up very gradually then we wouldn't get the start stop bunching either.

I'm afarid that you just have to accept that many of our roads have too many vehicles on them, they just weren't designed for this traffic volume, so you will see more and more of these schemes.

As for using the hard shoulder, I don't think that will work long term, as it is my understanding that the 3 lanes of a motorway and the hard shouldeer are built to different tolerances depending on the intended vehicle usage, ie lanes 1 and 2 have more foundation to cope with the heavier traffic, so I suspect the hard shoulders will get very rutted, break up, etc if subjected to heavy lorry use.

davidy

[Gixer]

Please no more.. I can't take anymore new labour crap. Hows about solving congestion by, get this, spending some of those milions of pounds the gov robs off the motorist every year on...... new roads. Here's another one when a new road is built, don't up the old one - like the old A13 through Rainham, was 2 lane then new A13 got built and now old one is one lane, 20' of bus lane and lights every few hundred yards. As are several other 'old' main roads I could mention. I fail to see how its a road improvement when you replace a congested 2 lane road with another and then degrade the original....thats kind of missing the point. Here's a good one lift the M25 crossing tolls like they were supposed to be so we no longer have to Q 2-3 junctions to get through. We have congestion in this country becuse the roads are designed to cause as much hold up as posible. It's 2006 and yet we are still stopped at red lights when there is nobody else around for miles, we 2 lane dual carriage ways built as a by-pass that are now single carriage ways with 30 foot of hatching and a 40mph limit, makingthe slower than the nsl roads they originaly by-passed


rant over

[Chas-Chiro]

As previously mentioned it failed on the M27 due to the road junction positon. People could not get enough speed to join the motorway after the lights so were joining at about 25-40mph depending on vehicle .
Trucks were suffering badly from this especially when joining uphill.

How about making the slip road longer with or without the lights for both merging and exiting traffic?

Edited by Chas-Chiro on Sunday 3rd September 03:18

[skinnyboy]

we have this on the freeways here in Melbourne, at rush hour the lights allow a series of cars to enter the freeway, its not rocket science, and it works rather well from my experience. All the Luddites on here might have trouble with it though....

[pringli]

works fine in california - where it is called "on ramp metering" one car goes per green and each lane is offset to allow one car a start - Yanks are not known for their ability when given a choice therefore they make it a rule! Freeway traffic lets them join too, causes much less rage than when you see the clever s****s/ impatient b*stds who try to force their way in when there is no gap instead of filtering.
No doubt drivers like TONY*13 would not understand how to proceed when confronted by such signals.

[BO55 VXR]

IMHO most motorway hold ups are caused by cars exitting/enterring motorways - We've all experienced the ws who either swoop across from outside lane to exit at the 100m board causing everyone else to take avoiding action which will then escalate all the way back until, at some point, the traffic comes to a stop

I think the idea of "local exit" lanes seem to work best, like J5/6 on M20

You have 2 or 3 lanes of motorway with a barrier down the inside, with another 2 lanes specifically for junction traffic. Every couple of miles, you have a gap in the barrier to allow traffic to leave/enter the motorway.

This gives drivers the oppertunety to get upto speed before enterring motorway or to allow drivers to exit at a more appropriately higher speed.

Mind you, wont really work over here as we dont have the space. Oh Well..

[elwe]

I think this system should work very well if its used as described on the highways agency site. I.e. only at times of peak traffic.

It has recently been tested on the bottom of the M3. I wish they would bring it to Junction 4 of the M3 as I have to queue here every morning beacuse the volume of traffic coming onto the motorway causes people in the inside and middle lanes to moveto the right where there isn't a space. THe result is the whole motorway becomes stop start for 1/2 a mile.

There appear to be a few misconceptions:
* This system SHOULD be used only during heavy traffic situations so no stopping at red lights at night.
* The lights change state very quickly beacuse only ONE car should go each time they go green.
* There shouldn't be a problem getting up to road speed. This system is being used BECAUSE the motorway is moving slowly.

Obviously the success all depends on the implementation, rather than the idea itself.