Hitting every traffic light green is the ideal, but how close do we actually get? Karl Tsigdinos reports.
I once commuted regularly from Dublin city centre to a suburban office. This meant driving along the Stillorgan dual carriageway at least twice a day. After months of hitting almost every red light, I discovered that if I drove exactly 63 miles per hour, I could get every traffic light green - from Donnybrook to Cherrywood.
That was two decades ago, when the word 'congestion' described blocked nasal passages and not Dublin traffic, so I was able to drive at speeds somewhat on the grey side of legal. But there was no incentive to travel at the speed limit; the 'reward' came when you sped.
Ironically, it took until last July for the traffic lights on the Stillorgan dual carriageway to be sequenced so that motorists travelling at the correct speed limit - 60 km/h - would get green lights all the way, traffic allowing.
Actually, only part of the road is properly sequenced, though the remainder will be sequenced soon, according to David Traynor, Traffic Officer with Dublin City Council. Even then, the lights will only be sequenced on the heavy peak traffic side (inbound in the morning, outbound in the evening).
"It's not physically possible for all lights on both directions of a major road to be sequenced," says Mr. Traynor, "so we emphasise the peak route."
At first glance, it would seem an impossibility to make any sense at all of Dublin's traffic lights, of which there are now nearly 700. Yet this is exactly what Mr Traynor and his colleagues in the Traffic Management section of Dublin City Council do every day.
Contrary to Dublin folklore, the traffic is not controlled by a few madmen in a control tower in Dublin's civic offices in Woodquay, hell bent on making commuters' lives a static hell.
Yes, there is such a control room, and yes, it has Big Brother-style screens monitoring every major Dublin junction. But it's a computer system called Sydney Coordinated Adaptive Traffic System (SCATS), which controls nearly two-thirds of all traffic lights in Dublin. SCATS analyses traffic flow in real time, and adjusts light sequences accordingly. Of course, the people in the DCC control room can take manual control; usually when there's been a major accident or an emergency, requiring them to increase the "green time" in a particular direction to get traffic moving. That is the only time they will intercede.
"We don't ever use traffic management to stop people from coming into the city centre," says Mr Traynor. "Absolutely not. I'd like to knock that on the head.
"But," he admits, "We may use it on side roads to stop rat runs."
Dublin is on the cutting edge of traffic management with the Australian-designed SCATS system, as it was the first city north of the Equator to adapt it. SCATS is now being used in cities in the USA, Poland, Israel, Singapore, as well as across Australia.
SCATS is a complex and flexible system that allows Dublin's traffic controllers to establish an almost infinite number of criteria for each set of lights. SCATS then chooses the correct sequencing based on traffic volumes in every direction. The so-called "green time" can range from just six seconds to nearly permanently green, though two minutes is the normal upward ceiling.
SCATS-controlled traffic lights can also recognise transponders and switch to green to facilitate vehicles carrying them. At present, only LUAS carriages have such transponders, but in the future buses and emergency vehicles will also have them.
'Surfing the green wave' - hitting every light green on a road - remains the ideal for every motorist. At the moment it's possible on the Finglas and Malahide roads, parts of the Stillorgan dual carriageway, and roads in Swords, Lucan, and Palmerstown, depending on other traffic and road conditions. And that's pretty much it.
Another problem for commuters is that four councils, South Dublin, Dún Laoghaire-Rathdown, Fingal, and Dublin City control Dublin's roads. For the moment, only DCC is using the SCATS system, although Dún Laoghaire is looking at it.
Elsewhere in the country, every single local authority controls what lights are placed where within its domain. Cork City is currently implementing a British-designed system called SCOOTS.
We motorists must shoulder much of the blame ourselves for the fact that we rarely, if ever, actually do 'surf the green wave.' That's because it takes us all so long to get moving when the light goes green: to get the handbrake off, to put down our mobile phones, make-up, or electric razors, and to engage our brains as well as first gear.
According to SCATS, considerably less than two-thirds of the cars are getting through the lights as should do.
The next time you're in traffic, count off how long it takes the cars in front of you to get moving once the light goes green. You'll find it's at least five seconds per vehicle, which is hard when the green light can last as little as six seconds. That's more like paddling in the green wave than surfing it.