Nigerian Monica Dongban-Mensem campaigns for road safety after her son died in a hit-and-run accident.

"Many Nigerians are impatient and it shows in their driving," Justice Dongban-Mensem tells the BBC.

She does not know who is responsible for her son's death but wants to tackle some of the poor driving she witnessed.

She started going to bus stations to speak to drivers about road safety in Nigeria, and what she found shocked her.

Most of the drivers had not received proper training and were not familiar with the traffic rules.

Such ignorance might have caused the death of her son and she is determined to change that.

The 62-year-old has set up a non-profit organisation named after her late son - Kwapda'as Road Safety Demand - to educate motorists about safety and she also plans to establish a driving school for potential commercial drivers, where they can receive training free-of-charge.

Not content with that, Justice Dongban-Mensem wanted to play a role in controlling the traffic herself. After weeks of training with the road safety commission she qualified as a traffic warden.