I Didn't Know That
0.0EndedDocumentary

I Didn't Know That

Industrial scientists Richard Ambrose and Jonny Phillips find extraordinary facts behind ordinary everyday objects.

5. Roads

0.0Oct 19, 2007 · 30 min

Did you know that just 1km of three-lane motorway costs £13 million to build? But what are our roads made of and what makes them so strong?