Amina Sohail veers through heavy traffic to pick up her next passenger –- the sight of a woman riding a motorcycle drawing stares in Pakistan's megacity of Karachi. "I don't focus on people, I don't speak to anyone or respond to the hooting, I do my work," said Sohail, who joined a local ride-hailing service at the start of the year, transporting women through the dusty back streets of the city.