According to Official Guinness Records,
The largest human wheelbarrow race was achieved by 1,554 participants (777 pairs) in an event organised for Guinness World Records Day, in Armidale, NSW, Australia, on November 6, 2009.
The majority of participants were school children from the region. The distance covered in the race was 50 m.
For a complete list of 2009 records, please visit 2009 Guinness Records in Afghanistan.