Traffic Robot: From Semaphores to ABB Safety Tech

How the traffic robot grew from police semaphores and Kinshasa's solar humanoids to Hangzhou's robot squad and automated flaggers, and where ABB tech could fit.

INDUSTRIAL ROBOTICS

Chat With Robot

10/6/20266 min read

Somebody has always had to stand in the middle of the road and decide who goes next. For about a century that was a police officer with white gloves and a whistle, and in many cities it still is. A traffic robot tries to take over part of that job: a machine that raises an arm, shows a signal or talks to people waiting at the curb. This post goes from the first gas lit semaphore in London to the aluminium traffic robots of Kinshasa, the robot squad now working Hangzhou's West Lake and the automated flaggers at road works, and asks where ABB robots and safety technology could fit.

Black and white photo of a policeman standing in a city street directing early motor cars
Black and white photo of a policeman standing in a city street directing early motor cars

A policeman directs cars in downtown Chicago, about 1917. Photo: National Archives and Records Administration via Wikimedia Commons (public domain)

How police officers and semaphores ran the crossings

The first signal of this kind went up outside the Houses of Parliament in London in December 1868. John Peake Knight designed it, and a police constable raised and lowered semaphore arms by day and worked a lever for red and green gas lamps at night. It exploded on 2 January 1869 and was taken down. Officers went back to directing traffic by hand, and through the early twentieth century the officer on a box or pedestal, waving his arms at trams, carts and the first cars, was a normal sight from Chicago to Brisbane.

Black and white street scene with a tram, old cars and cyclists and a policeman in the middle of the road
Black and white street scene with a tram, old cars and cyclists and a policeman in the middle of the road

A policeman directs trams, cars and cyclists on a Brisbane street in an archive photo. Photo: Queensland State Archives via Wikimedia Commons (public domain)

Electricity changed the job. Lester Wire, a Salt Lake City policeman, built an electric traffic light in 1912, and in August 1914 the American Traffic Signal Company installed one at East 105th Street and Euclid Avenue in Cleveland. In 1920 William Potts, signal superintendent for the Detroit police, added amber to make the three colour light, and in 1921 he put automatic lights in 15 towers across the city. Timers saved money: New York reassigned all but 500 of the 6,000 officers on its traffic squad. Denver ran computer controlled signals in 1952, and Toronto linked 159 signals to a computer in 1967.

Old printed photo of a busy city corner with streetcars, early cars and pedestrians
Old printed photo of a busy city corner with streetcars, early cars and pedestrians

East 105th Street and Euclid Avenue in Cleveland, where an electric traffic signal was installed in 1914, as printed in Engineering News that year. Photo: Engineering News via Wikimedia Commons (public domain)

The first machines built to look like a traffic officer came much later and from an unexpected place. Thérèse Izay Kirongozi, an industrial engineer in Kinshasa, designed humanoid traffic robots after seeing how easily drivers ran red lights and bribed their way out of fines. Her association, Women's Technology, installed two in Kinshasa toward the end of 2013. Each stands 2.5 metres tall, weighs 250 kg, is made of aluminium to cope with heat and heavy rain, runs on a solar panel and rotates its chest and raises its arms like an officer. By 2015 five were working in Kinshasa and one in Lubumbashi. The first ones cost about $15,000 each.

A tall silver humanoid robot with a green chest panel stands beside a group of women in a garden
A tall silver humanoid robot with a green chest panel stands beside a group of women in a garden

Thérèse Izay Kirongozi briefs Jill Biden and Ambassador Cathy Russell beside one of her traffic robots in Kinshasa, July 2014. Photo: David Lienemann / Wikimedia Commons (public domain)

Robot squads, flaggers and smart signals on the road today

The newest version of the idea is in China. China Daily Hong Kong reported on September 15, 2026 that the country's first traffic management robot squad, the 15 robot "Hangjing Zhixing" team in Hangzhou, had been upgraded. The robots went into full service over the May Day holiday and work next to traffic police, telling pedestrians and riders on non motorised vehicles when they are breaking the rules and giving directions to tourists. The upgrade lets them turn to watch every side of an intersection, plan their own routes, stop for obstacles and obey the lights at crossings. Since entering service they have given more than 230,000 reminders about violations.

An officer in a yellow vest stands in a wide intersection signalling to cars near an office building
An officer in a yellow vest stands in a wide intersection signalling to cars near an office building

A police officer directs traffic during signal maintenance at an Auckland intersection, 2007. Photo: Ingolfson / Wikimedia Commons (public domain)

Road works have their own version. A flagger with a stop and slow paddle has one of the most exposed jobs on the road, and since the early 1990s Automated Flagger Assistance Devices (AFADs) have let that person stand off to the side and work a signal head and a gate arm by remote control. Newer units add cameras and a tablet. A Minnesota Department of Transportation study found drivers approached them more slowly and stopped farther back than they did for a human flagger. On October 5, 2026, WPSD Local 6 reported that the Kentucky Transportation Cabinet is deploying more automated flaggers along with speed cameras in its work zones.

A mannequin robot in an orange uniform and hard hat holds a red flag behind plastic road barriers
A mannequin robot in an orange uniform and hard hat holds a red flag behind plastic road barriers

A robot flagger in orange workwear waves a flag at a road works closure in China, 2024. Photo: Fumikas Sagisavas / Wikimedia Commons (CC0)

ABB does not make traffic robots, and we found no ABB project in traffic control. Its products do solve some of the same problems. A Hangzhou robot that moves between corners has to find its way among people, which is what ABB's Flexley Mover AMRs do in factories with 3D Visual SLAM. A robot flagger that lowers a gate near workers needs limits on speed and reach, and ABB's SafeMove software sets those kinds of zones for industrial arms. These are possibilities only; ABB sells none of them for roads. Engineers usually try such motion and zone logic out first in RobotStudio.

A flat white and black ABB mobile robot on a glossy floor in front of a large red ABB logo
A flat white and black ABB mobile robot on a glossy floor in front of a large red ABB logo

The ABB Flexley Mover P604, which finds its way with 3D Visual SLAM. Photo: ABB

Where robot flaggers and AI signals go next

The bigger change at intersections will probably come from software inside the signal cabinet. ABC News reported on September 9, 2026 that AI controlled traffic lights are coming to Brisbane, with a human kept in the loop. Systems like that adjust signal timing from camera and detector data, and they need no arms or faces. A humanoid traffic robot mostly makes sense where it does something a light cannot: talking to pedestrians, pointing tourists the right way, or giving a work zone a visible figure that drivers notice.

A worker in an orange vest reaches into a black metal signal cabinet on a sidewalk corner
A worker in an orange vest reaches into a black metal signal cabinet on a sidewalk corner

A worker in a safety vest opens a traffic signal controller cabinet to run the lights by hand at a Chicago intersection, 2024. Photo: Kyah117 / Wikimedia Commons (CC BY 4.0)

The open problems are the ones Kinshasa ran into early. Cost is one: the 2015 generation cost about $27,500 per robot, and one estimate put the price of covering Kinshasa's roughly 600 dangerous intersections at $12 million. Authority is another, since the Hangzhou robots can remind people but cannot issue fines or arrest anyone, and AFADs still need a trained flagger in charge. Then there is safety around moving cars. Factory robots handle that with fences or with force limits like those in ABB's GoFa CRB 15000, which stops when it senses contact. Public streets have neither.

A woman guides a white ABB collaborative robot arm by hand at a table with boxes
A woman guides a white ABB collaborative robot arm by hand at a table with boxes

ABB's GoFa cobot is guided by hand and stops when it senses contact. Photo: ABB

For families, the most likely place to meet a traffic robot is still a road works site or a tourist district. The school gate is a different matter. Crossing guards who know the children by name are hard to replace, and few parents would want a machine making that call alone. Expect robots to take the most dangerous minutes of the job, at work zones and busy junctions, while people keep the decisions. Robots are moving onto streets in other ways too, as our posts on robotic pothole repair and sidewalk delivery fleets show.

Two engineers at a desk with a monitor beside a white controller cabinet and a robot behind glass
Two engineers at a desk with a monitor beside a white controller cabinet and a robot behind glass

Engineers with an ABB OmniCore controller and robot cell. Photo: ABB

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