The issue is control, not the sandal itself
Spain does not treat every pair of flip-flops as automatically forbidden driving footwear. The concern is whether a driver can operate the car safely. Spanish traffic rules require drivers to stay in control of their vehicles, and footwear that interferes with that control can become relevant during a stop or after an incident.
A loose sandal can shift underfoot, catch on a pedal, or slip off just as the driver needs to brake. Because braking and accelerating depend on quick, precise foot movements, even a small snag can delay a response. An officer who observes that a driver’s footwear is making pedal operation unsafe may treat it as a failure to drive with proper control, rather than cite a standalone “flip-flop” ban.
What makes footwear risky
The practical test is whether the shoe stays secure and lets the foot move freely between pedals. A sandal that hangs loosely from the toes is more likely to slide or catch than a closed shoe or a sandal with a firm heel strap. The same concern can apply to other footwear if it interferes with the pedals.
That distinction explains why the rule is not simply about what a driver is wearing: the relevant question is what the footwear does at the pedals. Choosing shoes that stay on the feet and allow reliable braking avoids turning a beach-day accessory into a roadside safety issue.
