Driving from Hull to Freetown, Siera Leone, with five vehicles to hand over to charity was no easy task as a new photographic exhibition at the Ferens Art Gallery explains.

The Hull Freedom Trail set off from Victoria Square, in Hull, a year ago with 24 people, five Mitsubishi L200s and a support truck. In just three weeks they made it to their destination – only to discover that Freetown had some of the worst roads in Africa.

The exhibition is full of colourful portraits of the Africans they met en route and information explaining key points of the journey – including a visit to the Moroccan city of Casablanca and a project which supports women who had children either through rape or outside marriage – which puts themselves and their offspring at risk of "honour" attacks.

In Mauritania they discovered a country still clinging to a tribal system of "gang masters cum landowners".

One photograph tells the story of Talib who escaped captivity only for his former tribal masters to sell his 15-year-old daughter to another family for marriage.

Amazingly a charity succeeded in taking the tribesmen to court and had the marriage quashed – but Talib has not seen his daughter since then.

The photographs were taken by Brough-based Justine McMillan and Hessle-based photographer Mark Kensett. They worked alongside Claudio von Planta, who recently shot the Long Way Down with Ewen McGregor and Charley Boorman and recorded the journey for a documentary film.

Mark said: "We shot about 8,000 images between us but the exhibition is a selection of around 60 of the photographs that we took. We did quite a lot of editing while we were on the journey as we posted photographs on the blog during the journey so the selection process had already taken place.

"Two hundred years after Wilberforce, slavery is still a big issue so what we are trying to do with the exhibition is remind people that this is something that still needs dealing with."

The 4x4s were donated to organisations in Sierra Leone to help repatriate families shattered by the recent civil war.

A book and Claudio von Planta's DVD of the journey, are available in the Ferens shop or by visiting www.hullfreedom trail.com.

The exhibition in the Liver Arts Space runs until October 26.