"作搭车手势" can be translated into English as "make a hitchhiking gesture" or "signal for a ride with a gesture".
The first phrase, "make a hitchhiking gesture," is more concise and commonly used in contexts where you're describing the action of extending a thumb or other hand signal to indicate a desire for a ride. The second phrase, "signal for a ride with a gesture," provides a bit more detail about the purpose of the gesture, which is to indicate a request for a ride. Both are correct, and the choice between them may depend on the specific context and level of detail desired.