In which cases, in accordance with the Road Traffic Rules, can a driver not be held liable for violating the established speed limits?

• 1If the speed-limit signs have been installed in violation of the rules for their introduction.
• 2If the speed-limit signs have been installed in violation of the requirements of national standards.
• 3If the speed-limit signs have been left in place after the elimination of the circumstances under which they were installed.
• 4Answers 1 and 2.
• 5Answers 1, 2, and 3.