Photographer Matthew Joseph took pictures of taxi drivers in six cities and asked what drew them to the profession.
"As a photographer it's people, faces, journeys and stories that fascinate me," says Joseph. "Taxi drivers tick these boxes in abundance."
Shot over a 12-month period, Joseph started the project in New York and moved to London, Paris, Rome and Johannesburg and ended in Cape Town.
Daniel, New York, USA
"I came here from Ghana to continue my degree. Driving a taxi gives me flexibility around my studies.
"There is a lot of competition now from Uber and other apps, but I think the Yellow Cab trade will survive - it will just look a lot different."
Themba, Cape Town, South Africa
"I came [to Cape Town] to study, but then I couldn't get a job after school, so I became a taxi driver. It's easy - no-one's telling me what to do."
Nathalie, Paris, France
"I met a taxi driver on a dating website, that's how I ended up here. I bought my licence for €170,000 (£146,700) nine-and-a-half years ago. I have only a couple of months to go until I have paid it off."
Jamal, Paris, France
"I love meeting people and being my own boss. I used to be an accountant but after being unemployed for a long time I decided to become a taxi driver. That was in 1992."
Rino, Rome, Italy
"It was more a family tradition than a choice to become a taxi driver 25 years ago. My parents pushed me into it - and here I am. I need the job but I don't love it - the best bit is that I get to practise my real passion, languages."
Allesandro, Rome, Italy
"I am my father's retirement plan. He was a taxi driver and I have been renting his licence from him since he has retired, as there is no retirement benefit as a taxi driver. I love doing what I do. I intend for this to be my full-time career.
"I think Uber here is not a problem, it's just competition. It's normal to have a rival on the job. This brings improvement to the trade. For example, most cars in Rome are now able to take card payments."
"I have been driving combi vans for eight years. I am doing this while I look for another job. My dream is to work for a big company one day."
"The potential to earn a decent living and the flexibility drew me to this job. It's the best market stall in the world - you can open and close whenever you want.
"Driving a black cab has been one of the few ways uneducated, working-class people can earn a decent income."
See more of Matthew Joseph's photographs on his website.