A century ago today, the world's first electric red lights traffic signals were switched on. Now, the devices appear to be heading for a dead end.
Traffic lights. Can't do with them, can't do without them. Or can we?
A century after the world's first electric signals were switched on at an intersection in Cleveland, Ohio, on August 5, 1914, traffic experts are contemplating a future of driverless cars regulating each other's speed without regard to red or green.
Although drivers stewing in Auckland peak-hour queues while waiting for an elusive "green wave" may dismiss that as a Silicon Valley pipe-dream, even the most pragmatic engineers have started envisaging a world without traffic lights.
"As you know, the future of traffic lights is there won't be any," says Auckland transport consultant John Gottler, who is vice-president of the Traffic Institute.
The big question is how long it will take for regulators to catch up with technology leaders such as Nissan, which hopes to have an automated car available for sale by 2018.
Mr Gottler acknowledges it will still be a long time before such cars saturate the market as a prerequisite for abolishing traffic lights.
"But we may be able to produce some better efficiencies with the new cars," he says.
An example would be onboard sensors putting the cars in the hands of intersection control boxes able to make them go faster or slower to optimise traffic flows through green lights.
Similar technology is already available on Auckland's new electric trains, to the occasional frustration of rail staff prevented by electronic controls from getting them up to full speed.
Fellow traffic engineer Urie Bezuidenhout says devising the mathematical algorithms needed to guarantee the safety of automated driving will be a huge challenge, but the technology is rushing ahead much faster than he would have predicted only a year ago.
"If you asked me then how long it would be, I would have said maybe 15 to 20 years, but now I reckon it's easily five to 10 years when you'll have the first driverless cars on the road ... "
Mr Gottler says lights work really well at intersections only with plenty of traffic - bunching vehicles into "platoons" and then sending them down corridors of co-ordinated green signals.
Roundabouts are generally more efficient at handling vehicle volumes of up to 40,000 a day, he argues.
Many cities in Europe and the United States have taken to switching lights off at night when there is insufficient traffic to keep them working efficiently, and reverting to simple "give way" rules, to save power and ease driver frustration.
An extreme example is in the Netherlands, where there is a big push by authorities to get drivers and pedestrians to make eye contact with one another while sharing space in low-speed streets.
But although Auckland has created several shared-space streets, Mr Gottler says government agencies here appear to have a lower opinion of drivers in resisting any move to turn traffic lights off at night.
"The argument here is that it is too confusing for drivers," he said.
Mr Bezuidenhout, who is developing a new algorithm to provide better estimates of lengths of queues or vehicles waiting at traffic lights, says drivers in his native South Africa are used to frequent power supply interruptions so tend to take in their stride traffic lights going out.
"If there is no signal it's a give way," he said. "But here the drivers assume if they think they are on a major route that they have the right of way.
"It's like they are completely ignorant as to how to behave when the signals go off," Mr Bezuidenhout said.
"I suppose it is because the power supply is so predictable it doesn't happen that often."
However, he acknowledged that Auckland drivers adjusted remarkably well during a regionwide power cut in 2006 when more than 700,000 people were left without electricity by a malfunction at the Otahuhu B substation, yet there were few scrapes at intersections.
"I think it affected a big enough area for people to realise it was more severe, so they were more careful."
Driverless cars or not, the North Canterbury town of Rangiora with a population of about 15,500 is meanwhile preparing to install its first two sets of traffic lights.
Local board chairwoman Sharleen Stirling says the town has seen an influx of new residents from earthquake-damaged Christchurch and needs the lights to bring order to a difficult dog-leg intersection at its Red Lion corner, which is being realigned.
• Drivers irked by traffic lights should be thankful they didn't live about 4000 years ago in the Mesopotamian city of Nineveh (now Mosul in Iraq), when clay tablet signs are reputed to have threatened the death penalty for anyone leaving a vehicle in the way of a temple procession.
• The world's first gas-lit traffic signals were installed in 1868 in London, opposite Parliament, but dismantled a month or so later after exploding and injuring a police officer who was operating them manually.
• A hundred years ago today, on August 5, 1914, the world's first electric traffic signal was switched on at the corner of Euclid Ave and East 105th St in Cleveland, Ohio.
• Auckland's first "vehicle-actuated" traffic lights - triggered by cars, trams, horse-drawn lorries or even bicycles running over rubber pads - began operating at the intersection of Customs and Albert Sts in June 1947, and were followed soon after by lights in Queen St with pedestrian push-button controls.
• The rubber pads were replaced in the late 1960s by magnetic wire loops under road surfaces, which since 1982 have been programmed through intersection control boxes by a centralised computer system called Scats (the Sydney Co-ordinated Adaptive Management System) now run from a joint Transport Agency-Auckland Transport traffic operations centre in Takapuna.
• Auckland has 801 sets of intersection traffic lights, and 88 motorway ramp signals, but Rangiora in North Canterbury is just getting around to installing its first two lights while Blenheim is still holding out against them.
Read about recent changes to Auckland's traffic light system here: tinyurl.com/aklredlights