TAIPEI, Sept 20 (AP) -- A Taiwanese engineer has been arguing with the government of the island's capital about the origins of a little green man who has been spotted all over the city.

When pedestrians cross streets in Taipei, traffic lights flash the image of a small, green human figure that speeds up his steps -- encouraging people to walk faster -- in the seconds before the light turns red.

Engineer Chang Ming-shun wants Taipei's city government to recognize him as the green figure's inventor. "As a father, I must establish my credibility with my little child, so I decided to stand up and speak out," he said Thursday.

But Taipei's Transportation Department said the design didn't belong to any one person. After considering Chang's original design, a team of experts had come up with a better version, said the department's Lin Li-yu.

"I felt his drawing of a person was not ideal, so we changed it," Lin said.