If you wish to enter an express highway or freeway, you must _________ before merging with the traffic.

To safely enter an express highway or freeway, moving to the acceleration lane is essential. The acceleration lane serves as a designated space for drivers to increase their speed to match the flow of traffic on the highway. This gradual increase in speed allows for a safer merging process, as it helps ensure that the driver can enter the highway without causing disruptions or hazards to other vehicles.

It's crucial to merge at a speed that is consistent with the surrounding traffic to promote safety for everyone on the road. While yielding to all traffic may apply in certain scenarios, it is specifically necessary to use the acceleration lane for speed adjustment before merging. The option of speeding up immediately without adequately using the designated lane can lead to unsafe conditions, while merging without signaling is not a safe or legal practice. Therefore, the correct course of action when entering an express highway is to first move to the acceleration lane to prepare for a smooth merge.