The IAAF/Cardiff University World Half Marathon will give Grangetown residents a chance to watch elite runners like Olympic champion Mo Farah in action.
Thousands of runners – including many local ones – will be taking part on Saturday afternoon with many more people watching in the streets.
The route for the second mile of the course will take the athletes down Sloper Road, past the Cardiff City Stadium, City Gardens and Ninian Park school before heading into Penarth Road and then out towards Penarth Marina and the Barrage.
Sloper Road and Penarth Road (from Grangetown station) will be closed to traffic for three hours from 12.30pm.
The first of the runners are expected at around 1.40pm. The men’s elite race starts at 2.10pm.
Cardiff Buses will also be affected – services 8 and 9 will start at end in Canal Street and not serve County Hall from 12:30pm until 4.15pm. The 92-95 services will also be affected.
Those taking part will include first-time runners from Grangetown who were picked as part of the Athletics for a Better World (ABW) project to encourage 500 people to take up running.
Some even won free trainers!
Good luck to everyone taking part – and don’t forget to cheer them on!