Julian Edgar, 50, has been writing about car modification and automotive technology for nearly 25 years. He has owned cars with two, three, four, five, six and eight cylinders; single turbo, twin turbo, supercharged, diesel and hybrid electric drivelines. He lists his transport interests as turbocharging, aerodynamics, suspension design and human-powered vehicles.
Do we need so many traffic lights?
Back when I was a kid, growing up in the northern suburbs of Adelaide, every six months or so there’d be some local excitement.
Normally it was presaged by a squealing of tyres, followed by a loud bang. On one occasion I can remember that after the bang there was the sound of an engine revving hard.
What had happened was a car crash at one of the local road intersections.
All the roads were grid-like; all used the ‘give way to the right’ rule – I don’t remember any ‘stop’ or ‘give way’ signs at those junctions.
The frequency of crashes was so high that when the right noises occurred in sequence, no-one stood around wondering what was going on: instead, everyone started running towards the scene.
Then, when I was about 13 or 14, the crashes suddenly stopped. What had happened was that small roundabouts had been placed in the intersections where crashes had most frequently occurred.
I don’t remember hearing a single crash from that point onwards. There might have been some minor bingles, but as the intersections had become quite tight, they would have been only at low speeds.
At the roundabouts drivers were travelling less quickly and were also required to be observant and participatory. Well, certainly less quickly, and more observant and participatory, than they had been when barrelling through a junction with just a cursory glance to the right.
I was reminded of my childhood because I have been increasingly hearing the idea that many traffic lights should be removed. That’s especially the case on secondary and tertiary (feeder) roads.
The arguments go like this:
• When traffic lights are green, people assume an absolute right of way. They don’t check for other cars and in fact, pay little attention to anything other than the colour of the light. So when crashes occur at traffic light controlled intersections, the impact speeds are high and so the crashes are likely to cause death or major injury.
• Even traffic lights controlled by smart systems (variable length time periods, sequencing of green lights on successive intersections) can, through prolonged idling times, cause increases in fuel consumption and emissions.
• The cost (both in installation and in running) of traffic lights is much higher than many other traffic control approaches.
It is being said by some that rather than giving driver apparent certainty, it is better in many situations to create uncertainty – to make the driver unsure of their surroundings. Perhaps the best example of that are those (rare in Australia) precincts that mix both pedestrian and vehicular traffic – cars just creep along at a walking pace.
Of course, in many applications traffic lights are just fine.
But the next time you’re out on the road in city conditions, note the dozens – perhaps hundreds – of traffic lights you pass, and start to consider: are these really necessary… or could this intersection have been handled in a different, simpler, cheaper and more effective way?
on April 21st, 2009 at 3:23 am
But… but… without Mr Trafficlight I would be responsible – if anything happened, I’d get blamed! What a terrible thought!
Sarcasm aside, I fully agree with you. It just seems that unnecessary traffic lights will stay for some time still because ‘we always did it that way’
on April 21st, 2009 at 11:12 am
If an intersection has even traffic flow then in my experience a roundabout is the optimal traffic control structure. They should replace traffic lights with roundabouts on many intersections throughout Victoria.
on April 21st, 2009 at 2:37 pm
In the past 6 months the 5km stretch of Anzac Parade in Sydney’s south east running from Maroubra Jn to La Perouse has seen the addition of two sets of traffic lights. So instead of three traffic lights previously, there are 5, with the two new ones placed at intersections with fairly quiet feeder roads. The first new set they put in appears completely useless. There is good vision in either direction for those turning from feeder roads – but now the infrequent motorist has to wait up to 30-45s for the lights to allow them on to Anzac Pde, needlessly holding up traffic in both directions. A roundabout isn’t really necessary, but would have been a much better option than lights.
on April 21st, 2009 at 4:28 pm
I actually believe they’re more suited to sporadic flows, an even flow often ends up with people stuck in the same manor they would be at a T-intersection on a busy road.
Lights and roundabouts could be combined to good effect on periodically busy intersections to avoid the above.
But single-lane each direction roads only! I’d wager 5% of the driving public genuinely know how to behave on multi-lane roundabouts, to see probably Australia’s worst implementation of this you need only look at Adelaide’s Brittania insurance premium elevator.
on April 21st, 2009 at 4:56 pm
Roundabouts are problematic if you have a lot of traffic coming from one direction and little traffic from other directions.
We have two such roundabouts in Maitland, and they regularly get long queues in peak periods, with risky behaviours regularly observed. At times it is nearly impossible to get out of one of the minor entries.
on April 21st, 2009 at 5:05 pm
Create uncertainty to make it safer. I like it.
You could apply the same methodolgy to speed limits as well. Remove most of those and place the responsibility back with the driver to actually think about what is a safe speed in their vehicle for the prevailing conditions (be that weather, traffic density or risk of pedestrian intreaction). No more dumb ‘blanket’ rules that are supposedly safe at any time in anything which leads to (some) drivers no longer thinking about the task of driving.
on April 21st, 2009 at 7:28 pm
Yeah, good luck with that – sounds like a recipe for chaos.
That’s why we have designated speed limits in the first place; too many people assume that they are “good drivers” on the basis of… well… nothing much more than their ego really. The trouble with this kind of utopian, libertarianist vision is that it ignores the fact that not everyone is a sane, solid citizen like you. “Blanket rules” are exactly what we need.
I doubt if the limits are designed to be “safe at any speed”; more like an indicative level of what’s safe given the local environment.
on April 21st, 2009 at 9:22 pm
There are plenty of roundabouts here in Canberra and I have to agree with the posters above who say that there is a limit to their effectiveness. When traffic volumes exceed a certain point they tend to clog up and don’t flow freely. There’s at least one near here with a set of lights just to pulse the traffic on one of the approach roads.
Below that magic traffic volume though, they are brilliant for keeping cars moving. There are still plenty of people who don’t seem to know the rules and indicate randomly or treat it as a stop sign and just about wait for a written invitation to enter, but a little anticipation and observation means they don’t pose too much of a problem, even on multilane ones.
The dangerous ones are where the road builders have installed a crown or fancy garden in the middle of the roundabout, blocking your view of other traffic. This can turn things into a bit of a lottery when someone does something a bit unexpected.
on April 22nd, 2009 at 7:47 am
It seems like many of the behaviour related problems mentioned here could be aleviated by educating the driving public more fully- that is surely something that could be done cheaply and at the responsibility of the driver. Bi-annual internet or community based education sessions, followed by a short written test on the concepts introduced? Failure to complete within a given period constituting a suspension of the driver’s licence.
Might sound harsh to some, but I thought we were all busily speeding around in 1400kg pieces of heavy machinery- perhaps a little care should be taken to ensure we do it well….
on April 22nd, 2009 at 9:45 am
Britannia roundabout in Adelaide would seem to suggest that roundabouts are no good for big, high traffic arterial.
I like the idea for suburban intersections though.
on April 22nd, 2009 at 10:38 am
Perhaps I should clarify that when I referred to an even flow of traffic what I meant was that the volume of traffic is equal from both directions of the roundabout so that any car can potentially move through the roundabout no matter which side they approach it from.
As has been suggested by others already, I think they are a better solution than traffic lights for many suburban intersections.
on April 22nd, 2009 at 12:43 pm
http://www.bbc.co.uk/dna/place-london/A303346
Roundabout rock except for the Hanger Lane one in West London. Makes the Brissy Airport roundabout look positively civil!
You have to see it sometime Julian
on April 23rd, 2009 at 10:31 pm
Roundabouts are dangerous for cyclists so I prefer traffic lights when cycling, but they are a pain when driving. Intelligent control of traffic light delays according to traffic volumes in each direction, and co-ordinating successive sets of lights, seems to be the best option to keep traffic moving.
on April 28th, 2009 at 10:16 am
Hmmm.
At Karalta Rd Erina and Central Coast Highway NSW they have a good compromise.
A roundabout operates normally when traffic is light.
When traffic becomes heavy a set of traffic lights begins to operate to govern the Central Coast Highway . It appears automatically operated from sensors .
It is the only place I have seen this operate but it works very well.
Regards Philip A
on May 4th, 2009 at 8:32 am
And maybe better urban design just might help with the “accident” situation.
I don’t like the word “accident” it implies that the situation is out of an individual’s control. A better term is “incident”, because when we are driving if we are not in control then who is?
Round-abouts are fine where traffic flows. When traffic’s gridlock they are a waste of time.
Round-abouts at large heavily trafficked intersections are stupid for exactly the reasons Jason from Canberra provided.
Round-abouts are the government not forward planning and not spending the appropriate amount of money to fix the flow problems associated with intersections and our roadways.
Where I live in Sydney the local government is indicating it will put a round-about at an intersection that is currently Stop sign controlled that has had a number of semi-serious incidents. The incidents are occurring because there is a high volume of traffic using the intersection and because the nearby main road (Warringah Road) is a parking lot in peak periods.
If the traffic on the main road flowed then there would be few drivers taking “short-cuts” and the Stop sign at the intersection I’m referring to (a residential street) would be adequate because only the residents would be using it.
By placing a round-about at the intersection will encourage more non-residents to use the “short-cut” because of “better flow” causing traffic problems at other intersections along the route.
If drivers weren’t so dicourteous and payed more attention while manouvering their 1 – 2+ tonne machine then I’d suggest that round-abouts at many intersections may work.
If you want to fix traffic flow problems then lobby the government.
Blogging won’t fix the problem.
on May 5th, 2009 at 9:23 am
I absolutely agree that roundabouts save lives and reduce injuries simply because cars have to slow down and any impacts are at oblique angles. Additionally one does not have to sit frustrated at a red light when no traffic is coming.
Further more drunks etc are much less likely to ram you side on, which they can do when they run a red.
Finally roundabouts add to the pleasure of driving more agile and responsive cars and may help to dissuade fools from using big dumb SUvs in the urban environment, which just has to benefit us all. Bob Jay
on May 12th, 2009 at 1:45 pm
Roundabouts require timing and skill when busy, how many drivers out there have skill or timing? For that matter know how to drive at all.
Roundabouts on main arterials? No way, accidents galore. Not only that, Sydney drivers all sit in the middle of intersections at red lights so people from the other direction would never get through because of discourteous @$%3holes.
I have seen old people at roundabouts turn right into onciming traffic because they can’t figure it out. UNfortunately we always cater to the lowest common denominator rather than removing from the breeding pool.
on June 2nd, 2009 at 5:52 pm
I like the concept of reducing idiot signs and getting drivers thinking. P platers would learn really quick they arnt being held by the hand so there would be nothing to rebel against. Experience counts and what sort of experience do you get when every move you take is mandated (signs, roundabouts, overbouts, lights etc). We are required by law to drive responsibly so take away the excuses. Make the driver look and think, turn off the phone turn down the radio, put away the hair brush, stop drinking the coffee. Drivers have to realise they are the problem
If no signs ever tell you a speed hump (overbout) is coming and no white paint highlights it’s lift then you bet after the first thump every driver will slow down. (bumps reengineered for effect at max speed limit for area)
We have a major tailgating issue in Australia because people feel to confident in themselves reading the road ahead, more uncertainty will produce safer driving.
on July 21st, 2009 at 10:59 pm
Here in Albury, NSW, not only have the council put in an annoying amount of traffic lights throughout the city, they are to narrow the northern approach to Albury at Lavington (5 ways intersection), from 2 lanes each way to 1 lane each way through the shopping centre, where at the moment it is 60 kmph.
The council uses the excuse of slowing the traffic, ( Albury Council refers to that as “traffic calming”), but it could have done that years ago by changing the speed signs in that area to 50kmph or if necessary to 40kmph.
This will cause a bottleneck at this vicinity for the main part of the day.
The council have been doing this for a number of years now; narrowing streets , not building footpaths, and then we have pedestrians with pushers, etc., on a narrowed road mixing more closely with motor vehicles unnecessarily.
They are building a few roundabouts here and there, but I feel that the council as well as the RTA regard roundabouts unsuitable for busy roads where there is a large amount of traffic.
I, myself still feel that a well designed roundabout at Lavington, would be better than the traffic lights, especially if they could incorporate as Philip Armbruster from the NSW Central Coast gives the example of the roundabout with traffic lights which will operate when traffic gets heavy.
There has to be a better way in our cities for traffic to flow unimpeded.
Our country cities are catching up with the congestion of Sydney/Melbourne, (still a bit to go yet), so you would think the authorities/councils, would have the personnel with the technical and practical knowhow to come up with something out of the square to alleviate this ongoing problem.
I think they just take the easy way out and are not too concerned about this problem as it’s ‘only a job’.
on October 3rd, 2009 at 1:57 pm
I’ve known this for years-
The best system is a traffic light that shows all roads orange at the same time, so people driving up to a green light see it turn orange, and people sitting on a red light see a red and orange together and can get ready for the green.
That gets cars off the mark faster.
Then unless the traffic is at peak flow all the lights flash orange on and off and the intersection works as a traffic island- Give way to your right.
Easy to do with a little re-programming of the current lights, but of course these things are run by Govts and not the free market-
they have NO interest in being efficient!