What is the best practice for merging onto a highway?

Merging onto a highway requires a driver to integrate into an existing flow of traffic safely and effectively. The best practice is to speed up to match the traffic flow. This is crucial because maintaining a similar speed to the vehicles already on the highway minimizes the risk of disrupting traffic and reduces the chances of accidents. When a driver accelerates to match the flow, they create a smoother transition, allowing for a safer merge.

Countries and regions often have guidelines that emphasize matching speed while merging to improve overall traffic safety and efficiency. This approach helps other drivers anticipate your actions, as they can more easily adjust their speed or position in response to your merge.

The other options do not promote safe merging practices. Slowing down considerably may cause confusion for drivers already on the highway and can increase the risk of collisions. Checking the rearview mirror only limits a driver's awareness of their surroundings, as it's essential to also check blind spots for vehicles that may be in adjacent lanes. Merging without signaling fails to communicate a driver’s intentions to others on the road, which is critical for safe merging and overall traffic management.