Final answer:
Motorcyclists should use extra caution when encountering pavement grooves, which are designed to increase traction and reduce skidding. They should not ignore the grooves, increase speed, or take a different route. Option 1.
Step-by-step explanation:
When motorcyclists encounter grooves in the pavement, which are designed to prevent slippery conditions in wet weather, they should use extra caution. The presence of safety grooving, a technique developed to increase traction on surfaces, is meant to decrease skidding, reduce stopping distance, and improve a vehicle's cornering abilities. However, for motorcyclists, these grooves can still present a unique hazard as the motorcycle's tires can react differently compared to those of a car.
Rather than increasing speed, ignoring the grooves, or finding a different route, motorcyclists should adjust their riding to the road conditions, which includes slowing down, maintaining a steady throttle, and using gentle maneuvers. By being cautious, they increase their safety and ensure better control over their motorcycle.