They swerve onto sidewalks, zip between traffic and dart up the wrong way, sometimes with entire families piled on top of their motorcycle taxis, adding to the chaos of this African mega-city. Now the government is saying not so fast to the estimated one million motorcycle taxi drivers in Lagos and the surrounding area who are blamed for causing many of the deadly crashes on the city's roads.New rules will prohibit them from carrying pregnant women or children. Authorities say they will be stopped from driving up the wrong way, and the roads they will be authorised to travel on will be sharply reduced.But the drivers themselves, who scrape out a meagre living hustling passengers between, around and through Lagos's legendary traffic jams, argue that the rules go too far."Life is not certain here," said Linus Achagwu, a 31-year-old driver of a motorcycle taxi, which are locally called "okada." "I still need to be financially equipped. The cost of living in Lagos state is high."The danger the motorcycles pose is evident to anyone who has ever attempted to cross a road in Lagos, a sprawling city of some 15 million people which rivals Cairo as Africa's largest. Walking the sidewalks even carries risks since riders often use them for shortcuts.The government in Lagos state, which includes the city and its surroundings, says up to three-quarters of accidents in recent months have been motorcycle-related.But road safety is not the only concern. Authorities say armed robbers operating on motorcycles are responsible for more than 70% of crimes, including car burglaries and snatching cash from customers leaving banks. More rules and restrictions will help control them, officials say.Beginning on September 1, motorcycle drivers will no longer be allowed to carry pregnant women or children. Mothers with a child on their back inside a wrap will not be permitted, either. Entire swathes of the city will be out of bounds for motorcycles, and that has raised questions about how anyone will get anywhere even nearly on time due to the maddening traffic.Existing laws will also be enforced, officials say. That means no driving the wrong way.Parents often use the bikes to get their children to school, and five people can sometimes be spotted on one. Only one passenger will now be permitted."For children taking okada to school ... it's a risk," said Regina Robert (29). "But we can't help it. Taxis are expensive."She was standing on the roadside in Lagos' Obalende district, a hub for buses and motorcycles. Bikes swarmed in and out of the crowds, their horns blowing repeatedly, while bus drivers called out to potential passengers and market sellers hawked furniture, food and electronics.A group of worshippers were at a makeshift mosque under an overpass, while one man wearing headphones watched a ragtag football match as he sat atop a horse. It was another Friday at rush hour in Lagos, further complicated by a presidential visit that had tied up roads more than usual.But despite the difficulties of navigating this city, government officials said they have no choice but to restrict bikes."The reason why a good number of people will ride on the bike is not because they have no other alternatives," said Jonas Agwu, a federal official in charge of road safety for Lagos."It is because they want to get to their destination faster and avoid the traffic build up."Commuters must plan ahead and take advantage of bus routes, he said. But his argument is not likely to convince those accustomed to waiting in traffic for hours for journeys that should take a fraction of that time."I think the man who is alive can talk about where he is going," said Agwu. "A dead man cannot."Several mothers at Obalende on Friday agreed with the rule prohibiting children, saying the risk was too great for them."I think it's a good idea," said Rabi Umar, a 33-year-old who carried an eight-month-old girl on her back. "Schools should have buses."Drivers say they are mostly hard-working people supporting families. They question how they will continue to make a living. "We are using this okada as a means of survival," said driverGodwin Ekong.Achagwu, the 31-year-old bike driver, saved money for his motorcycle by working as a wheelbarrow pusher -- another group of workers who ply Lagos roadsides. He lives in a tiny apartment with his wife, who became ill while pregnant and lost what would have been their first child. He says the new rules may force many riders out of business."If you stop them from doing it, what would they do?" he said.