12 April 2011

Do we need an integrated traffic management system?

| beejay76
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I just drove from Harrison to Belconnen. I hopped down the GDE, stopping at every intersection for a red light. Then I stopped at every intersection on Gininderra Drive, then I stopped at every intersection on Coulter. By the end, I was getting the right royals, I don’t mind telling you. I’m not generally prone to road rage, but honestly!

It got me thinking about the light phasing. In Sydney, there’s a system called SCATS which manages the phasing of traffic lights to maximise the even flow of traffic. I’m guessing we don’t have anything like that in Canberra.

While Canberra doesn’t have anything like the congestion problems that Sydney has, there have been so many times where the shocking light phasing seems to stuff up the traffic. As I was watching all the cars around me stop every 15 seconds or so, even though the traffic was light, it made me wonder how much extra fuel is being wasted, and how much more carbon is therefore emitted, simply by poor phasing of traffic lights.

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With the cost of installation and maintenance of a set of traffic lights (which no one seems to have the advanced skills to program correctly anyway), maybe it would actually be cheaper to just train and hire unemployed workers to direct traffic at intersections with lollypops during the busier periods. Then at least one would think we would achieve both intelligence and fairness in traffic management at an intersection.

damien haas said :

Some traffic lights seem totally unnecesary, i think there are several sets on Ginninderra Drive that could be replced by a roundabout, benefitiing everyone. A new set of lights has just been installed in Kaleen, which would have been better as a roundabout. In fact, im noticing a general trend away from roundabouts to traffic lights.

That intersection would have been perfect, rather than the current ones that are timed, dont have sensors and I reckon have made traffic flow worse. And dont even get me started how they concreted and painted in a majority of the slip lane to turn into Kaleen which backs up the right lane of traffic, not sure what genius thought that was a good idea…

TAMSMediaRoom10:20 am 13 Oct 11

Canberra uses SCATS to control the traffic lights. This is the same system used in NSW. As a general rule, Territory and Municipal Services (TAMS) coordinates the traffic lights on arterial roads to favour the peak direction of traffic, eg towards the City in the morning, away from it in the afternoon.

Coordination outside peak periods is more difficult because traffic flows along the arterial roads are not predominantly in one direction or the other. As main road flows are much lighter, drivers on the side roads or pedestrians trying to cross can get frustrated waiting on what seems like long red lights that often result from coordinated fixed-cycle time operation.

For that reason not all arterial roads are coordinated during off peak periods. However TAMS is actively looking to see if overall benefits can be achieved by introducing coordination on more of these routes during off peak periods.

SCATS hasn’t really been updated since the 1980’s – bit of tweaking for Olympics but that was it. Check out Mall of America, or several cities in California that have the more up to date.
Australia used to have a lot of good Traffic management Engineers – mainly with AWA (who actually did most of SCATS for RTA), most have since headed overseas – US, Middle East and South East Asia (especially Singapore) being the usual destinations.

wallabyted said :

In Dec 1980 the ABS estimated the population of Canberra at around 230,000. In Mar 2011 the ABS put the ACT population at around 360,000. In the early 1980s there were very few sets of traffic lights (round abouts were more favoured) and the speed limits on most arterial roads (eg Northbourne Ave) was much higher than today.
I would estimate qualitatively that even though our population has increased by less than 50% over the last thirty years, our traffic has increased by a factor of at least 10. I don’t remember traffic issues anywhere in Canberra back in the early eighties. I think it is the traffic lights that have created our traffic problems by starting and stopping traffic – noting that a significant portion of the time, traffic lights stop traffic in ALL directions. Perhaps another contributing factor might be that many single carraigeways have remained that way under increased traffic flow. Its time our planners did a proper study of traffic flows. If using an external consultant it should be sure the consultancy doesn’t present a conflict of interest in that the consultant should not be allowed to directly or indirectly sell the solution.
As an aside, the TAMS site mentioned in previous posts states “In light to medium traffic conditions, roundabouts can cause less delay to traffic movement than traffic lights. In these instances the relatively low maintenance costs of roundabouts will mean that their installation is preferred.” – but I don’t think they have been following their own stated policy on this one of late.

There has definitely been a significant increase in the installation of traffic lights vs roundabouts in Canberra over the last 20 years. My gut feeling (without facts behind it I am willing to admit) is that you are right.

Cost probably has been the decision making factor here.

In Dec 1980 the ABS estimated the population of Canberra at around 230,000. In Mar 2011 the ABS put the ACT population at around 360,000. In the early 1980s there were very few sets of traffic lights (round abouts were more favoured) and the speed limits on most arterial roads (eg Northbourne Ave) was much higher than today.
I would estimate qualitatively that even though our population has increased by less than 50% over the last thirty years, our traffic has increased by a factor of at least 10. I don’t remember traffic issues anywhere in Canberra back in the early eighties. I think it is the traffic lights that have created our traffic problems by starting and stopping traffic – noting that a significant portion of the time, traffic lights stop traffic in ALL directions. Perhaps another contributing factor might be that many single carraigeways have remained that way under increased traffic flow. Its time our planners did a proper study of traffic flows. If using an external consultant it should be sure the consultancy doesn’t present a conflict of interest in that the consultant should not be allowed to directly or indirectly sell the solution.
As an aside, the TAMS site mentioned in previous posts states “In light to medium traffic conditions, roundabouts can cause less delay to traffic movement than traffic lights. In these instances the relatively low maintenance costs of roundabouts will mean that their installation is preferred.” – but I don’t think they have been following their own stated policy on this one of late.

montana said :

“I just drove from Harrison to Belconnen. I hopped down the GDE, stopping at every intersection for a red light. Then I stopped at every intersection on Gininderra Drive, then I stopped at every intersection on Coulter.”

am i the only person who has noticed the OP has taken the longest possible route to belconnen?

Nup. It’s the shortest. Shorter than going via Gundaroo, shorter than Billy Slim. However, am now questioning whether it’s the *fastest*…

“I just drove from Harrison to Belconnen. I hopped down the GDE, stopping at every intersection for a red light. Then I stopped at every intersection on Gininderra Drive, then I stopped at every intersection on Coulter.”

am i the only person who has noticed the OP has taken the longest possible route to belconnen?

Thoroughly Smashed said :

beejay76 said :

Spectra said :

It got me thinking about the light phasing. In Sydney, there’s a system called SCATS which manages the phasing of traffic lights to maximise the even flow of traffic. I’m guessing we don’t have anything like that in Canberra.

Yeah, if only we had something like that. (3rd paragraph, in case you’re not much for reading).

…I used to travel up Drakeford drive and onto the parkway…

Because I’m sure nobody’s ever even thought about that….

Seriously people, 5 minutes with Google.

Thanks for the link. It confirms there is no coordination along those major roads. Every time a car approaches from a side street, the entire main thoroughfare is brought to a halt. Most irritating. At one intersection on Gininderra, I watched it go red (from my position pulling out of the previous red light) because a single car had arrived from a side street. There were about 20 cars halted along Gininderra to allow a single car minimal waiting time.

How on earth did you draw that conclusion from that article?

From the description of “modes of operation”. Isolated = exactly what we see along the major roads, at least outside of peak times. I haven’t seen anything like the ‘”coordinated” description, although I don’t drive at peak times, or perhaps not on the roads where they are.

Thoroughly Smashed9:39 am 15 Apr 11

beejay76 said :

Spectra said :

It got me thinking about the light phasing. In Sydney, there’s a system called SCATS which manages the phasing of traffic lights to maximise the even flow of traffic. I’m guessing we don’t have anything like that in Canberra.

Yeah, if only we had something like that. (3rd paragraph, in case you’re not much for reading).

…I used to travel up Drakeford drive and onto the parkway…

Because I’m sure nobody’s ever even thought about that….

Seriously people, 5 minutes with Google.

Thanks for the link. It confirms there is no coordination along those major roads. Every time a car approaches from a side street, the entire main thoroughfare is brought to a halt. Most irritating. At one intersection on Gininderra, I watched it go red (from my position pulling out of the previous red light) because a single car had arrived from a side street. There were about 20 cars halted along Gininderra to allow a single car minimal waiting time.

How on earth did you draw that conclusion from that article?

damien haas said :

There is a whole raft of very poor technical and planning decisions made by Roads ACT. Ive often wondered why with all thw continuing expense of thw GDE, there are still traffic lights where it passes over the Barton Highway, Ginninderra Drive and Belconnen Way.

Logically all four MAJOR roads would be better served if traffic flow was uninterrupted, but no, traffic lights to access the GDE go on and off with no real algorithm. Its easy to mock the cloverleaf flyovers of the US highway system, but at least the traffic keeps moving.

I’ve often wondered why the only cloverleaf in the whole system is from Barton Hwy onto the GDE heading towards mitchell. The answer from Roads ACT would probably be something to do with cost, but considering what they’ve been willing to spend on the abomination so far……?

There is a whole raft of very poor technical and planning decisions made by Roads ACT. Ive often wondered why with all thw continuing expense of thw GDE, there are still traffic lights where it passes over the Barton Highway, Ginninderra Drive and Belconnen Way.

Logically all four MAJOR roads would be better served if traffic flow was uninterrupted, but no, traffic lights to access the GDE go on and off with no real algorithm. Its easy to mock the cloverleaf flyovers of the US highway system, but at least the traffic keeps moving.

troll-sniffer said :

Just as a teensy weensy spanner in the works for the synchronised lights brigade… can anyone with a grasp on reality and with their head not up their theoretical arse please inform the forum how you propose to get synchronisation in both directions of a major arterial road? If you get a synchro wave going in one direction, it will certainly not work as one for the cars going the opposite way.

Think about

That was unnecessarily pejorative, I think!

I don’t think anybody’s arguing that it will work in both directions simultaneously. It works in the major traffic flow direction. In Sydney it’s dynamic, so phasing changes depending on the need of the area at a given time, not just some rubbish programmed from a clock. That is what SCATS is, if you’d read the link.

Time to reevaluate heads and arses, troll-sniffer.

I forgot to add that, if properly designed, roundabouts can give permanent and continuous access priority to public transport and T2/T3 vehicles. They can either enter the roundabout in their own lane from the left or, if vehicles already on the roundabout are calmed/speed limited to around 40km/h, those vehicles can be forced to give way to priority vehicles entering the roundabout from the right hand lane.

Also, has anyone noticed at intersections that, even though some traffic lights on a loop go green for traffic even when cars aren’t there, they don’t seem to ever go green for pedestrians and cyclists unless they push the button. Traffic lights could be improved, without interrupting the flow of traffic, so that pedestrians and cyclists can automatically cross (even half way to a traffic island is better than nothing) when cars are not travelling in that direction. And people wonder why pedestrians and cyclists run red lights or, worse, push the button and cross against the red light anyway….

wildturkeycanoe9:49 am 13 Apr 11

I have pointed out here [on RA] before that there was a rather expensive study done on the traffic of ants and how that could be used to improve our own traffic systems. Results?? None that I’m aware of except a large chunk of money given to a dumbass to sit and watch ants all day. The fact that they can “drive” over each other in a front collision situation is a big advantage to what we put up with and they all respect the queen so much they wouldn’t dare disobey the rules.
Seriously though, there are lots of lights out there which have a “time of day” sequence, where they seem to let major roads have the priority, but this also applies on weekends. I’ve sat at intersections for up to 2 minutes waiting for nobody whilst the red light smirks at my frustration. Then there’s also the major thoroughfares that go red for…..well, inconvenience I suppose, as no cars come through but flags you down just for the heck of it.
Let’s bugger off the lights and let everyone fend for themselves, I’ll get to work much quicker that way. Just have to get that job working for an aerospace technologies company who’ll give me a fly-in-fly-out option as part of the package.

troll-sniffer said :

If you get a synchro wave going in one direction, it will certainly not work as one for the cars going the opposite way.

Only if you stick with convention. It is possible to have two ‘waves’ going in opposite directions. Not saying it will work, just saying it’s possible!

Traffic management is one of those things where everyone thinks it’s done poorly. But I’m sure if you spent a few days learning about it you’d be like… “Ohhhhhhhhhh riiiiiiiight! Duh!”

Still, I can’t escape the feeling that the infrastructure is locked in a time warp – surely there are modern solutions to the problems and constraints the system presents.

troll-sniffer9:19 am 13 Apr 11

Just as a teensy weensy spanner in the works for the synchronised lights brigade… can anyone with a grasp on reality and with their head not up their theoretical arse please inform the forum how you propose to get synchronisation in both directions of a major arterial road? If you get a synchro wave going in one direction, it will certainly not work as one for the cars going the opposite way.

Think about

#11 gentoopenguin

+1 re synchronised traffic lights that assume a lower average speed than the speed limit. As well as environmental benefits and encouraging cultural change, it allows cars starting from a red light to “get with the flow of traffic” rather than being out of synch the whole trip. Northbourne Ave is a good example. If you are going through the Alinga St intersection when the light goes yellow, you can’t possibly make the London Circuit intersection without flooring it (interestingly, isn’t that where there is a red light camera?).

Also, I read that Stanhope says that roundabouts can cost up to $1.5m vs $600k for traffic lights which I found very surprising (eg surely ongoing maintenance of traffic lights (including costs of synchronising), costs of more serious accidents at traffic lights and higher individual costs of fuel and wear and tear would mean roundabouts are more economically viable). However, I still think the merits of roundabouts (with traffic lights to control peak flows if necessary) outweigh intersections with traffic lights only. I think my view is in the minority though as apparently the recent Canberra Times survey suggested that less people like roundabouts with traffic lights because they think that it would confuse drivers.

One day the ACT Government and Roads ACT will move into the 21st Century. There is virtually no effort or ability in this city to even attempt to coordinate the traffic lights to make traffic flow smoothly which means almost every arterial road with multiple sets of traffic lights are stop and start all the way along.

I now avoid Yamba Dr between Isaacs and Hughes whenever possible due to the traffic lights adding 5+ minutes to the journey as you stop at each set. Northbourne Avenue is the same, if not worse. Then you add in the intersections where the light sequence is too short to clear the traffic and the ones where you and the other traffic wait for 5 minutes while the opposite direction stays green for zero traffic and the shemozzle is complete.

I’m not really holding my breath with hope that things might change with the current government and departments.

Chief Ten Beers10:46 pm 12 Apr 11

gentoopenguin, thats germany for you! Here in Australia cars are bad. Cars are evil and drivers should be punished.I would not be surprised if they put in a priority bike crossing traffic light before they even start to realize the benefits of an intelligent traffic system.

damien haas said :

Some traffic lights seem totally unnecesary, i think there are several sets on Ginninderra Drive that could be replced by a roundabout, benefitiing everyone. A new set of lights has just been installed in Kaleen, which would have been better as a roundabout. In fact, im noticing a general trend away from roundabouts to traffic lights.

Even better Damian some of the ‘new’ intersections shouldn’t have been built. Same too with the ‘new’ one on Gungahlin Drive near Mitchell going into Harrison (I think).

Major roads like Ginninderra Drive should feed main roads that go around a suburb, not into the middle of the suburb. It cuts down on the number of roads off the main road.

gentoopenguin6:03 pm 12 Apr 11

Having spent most of my life in Germany, I can only recommend Aussie (and in particular, ACT) traffic planners having a look overseas. “Intelligent” traffic lights have been the standard there for many years. Without these, German traffic within the major cities would have collapsed by now. The so called “green wave” also rewards drivers for driving at or just below the speed limit: You get one set of green lights after the next. Speeding won’t help because the lights would still be red once you arrive. And, as beejay76 mentioned correctly, there is quite an environmental effect too – the green wave lowers pollution, petrol use and noise … and, drivers are less stressed!

Btw, is there ANYONE in ACT Government reading RIOTACT? I so would not care about them snapping up the online community’s excellent ideas … if they only DID something …

Some traffic lights seem totally unnecesary, i think there are several sets on Ginninderra Drive that could be replced by a roundabout, benefitiing everyone. A new set of lights has just been installed in Kaleen, which would have been better as a roundabout. In fact, im noticing a general trend away from roundabouts to traffic lights.

Spectra said :

It got me thinking about the light phasing. In Sydney, there’s a system called SCATS which manages the phasing of traffic lights to maximise the even flow of traffic. I’m guessing we don’t have anything like that in Canberra.

Yeah, if only we had something like that. (3rd paragraph, in case you’re not much for reading).

…I used to travel up Drakeford drive and onto the parkway…

Because I’m sure nobody’s ever even thought about that….

Seriously people, 5 minutes with Google.

Thanks for the link. It confirms there is no coordination along those major roads. Every time a car approaches from a side street, the entire main thoroughfare is brought to a halt. Most irritating. At one intersection on Gininderra, I watched it go red (from my position pulling out of the previous red light) because a single car had arrived from a side street. There were about 20 cars halted along Gininderra to allow a single car minimal waiting time.

I bet you the person who came up with that acronym is having a good chuckle… Seriously the “S” (Sydney) was not necessary.

I some cases simple sensors could improve things a lot. I often have the problem of turning onto a road where there is no traffic. The light stays red until some traffic finally appears, at which time the light changes to stop them and let me through.

So SCATS is supposed to stop you getting the s***s? 🙂

Damn you, captainwhorebags. How am I meant to beat you to posting the same information if you don’t spend as much time as me adding snarky comments?

It got me thinking about the light phasing. In Sydney, there’s a system called SCATS which manages the phasing of traffic lights to maximise the even flow of traffic. I’m guessing we don’t have anything like that in Canberra.

Yeah, if only we had something like that. (3rd paragraph, in case you’re not much for reading).

…I used to travel up Drakeford drive and onto the parkway…

Because I’m sure nobody’s ever even thought about that….

Seriously people, 5 minutes with Google.

captainwhorebags2:38 pm 12 Apr 11

This will answer your questions, including an explanation of why it may appear that lights are not co-ordinated at peak times on Drakeford Drive.

http://www.tams.act.gov.au/move/roads/traffic/trafficsignals

georgesgenitals2:28 pm 12 Apr 11

Many years ago when I lived in south Tuggers, I used to travel up Drakeford drive and onto the parkway. I worked out that if you sat on 80km/h, you couldn’t get more than a couple of sets of lights green in a row. If, however, you started at the right time, and travelled at 95km/h, you could do the entire thing with green lights.

And I never got a ticket once.

Having smarter phasing of traffic lights to maximise traffic flow should be a given.

I’ve said it here before, traffic lights in their current form are technological dinosaurs. They essentially have not changed decades with the exception of going to LEDs. I’m amazed that there’s been barely any innovation in that whole time.

Sometimes they seem malicious – there’s just no way they could randomly be THAT bad.

In a previous thread here I think there was some discussion of a few managed sets of lights in the city.

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