The blue flag serves as a crucial race marshal signal indicating that a faster driver is approaching from behind to lap slower traffic. Understanding and responding correctly to blue flags is essential race craft, with specific rules governing how both the faster and slower drivers should behave.
Blue flag protocols:
- Stationary blue flag: Indicates a faster kart is approaching but not yet close enough to overtake
- Waved blue flag: Requires the slower driver to allow the faster kart to pass immediately at the next safe opportunity
- Slower drivers must not defend their position or block faster traffic
- Failure to observe blue flags may result in penalties or disqualification
The faster driver maintains responsibility for completing the pass safely, but the slower driver must facilitate this by holding their racing line predictably or moving off-line at a safe location. Repeatedly ignoring blue flags is considered unsporting behaviour and will be penalised by race officials. At national-level events, drivers typically have three corners to respond to a waved blue flag before penalties are applied.