Final answer:
The statement is true. You must obey all signs and signals unless directed otherwise by a police officer. Traffic signs and signals are there to ensure safety and order on the roads.
Step-by-step explanation:
The statement 'Unless directed by a police officer, you must obey all signs and signals' is generally true. Traffic signs and signals are the basic means by which traffic is regulated. Everyone who uses the roadways is required to be aware of and obey the traffic laws, which include obeying all traffic signs and signals unless you are directed otherwise by a police officer.
The presence of a police officer supersedes the usual traffic controls because the officer may be responding to an emergency, directing traffic in a different manner, or overriding the signs for safety or traffic flow reasons. When no officer is present, signs and signals are the rules that govern the road, such as telling vehicles when to stop, yield, or the speed limit that should be adhered to. These measures are designed to ensure safety and order on the roads.