This case is a petition assailing the validity or the constitutionality of a Letter of Instruction No. 229, issued by President Ferdinand E. Marcos, requiring all vehicle owners, users or drivers to procure early warning devices to be installed a distance away from such vehicle when it stalls or is disabled. In compliance with such letter of instruction, the Commissioner of the Land Transportation Office issued Administrative Order No. 1 directing the compliance thereof.
This petition alleges that such letter of instruction and subsequent administrative order are unlawful and unconstitutional as it violates the provisions on due process, equal protection of the law and undue delegation of police power.
Whether or not the Letter of Instruction No. 229 and the subsequent Administrative Order issued is unconstitutional
The Supreme Court ruled for the dismissal of the petition. The statutes in question are deemed not unconstitutional. These were definitely in the exercise of police power as such was established to promote public welfare and public safety. In fact, the letter of instruction is based on the constitutional provision of adopting to the generally accepted principles of international law as part of the law of the land. The letter of instruction mentions, as its premise and basis, the resolutions of the 1968 Vienna Convention on Road Signs and Signals and the discussions on traffic safety by the United Nations - that such letter was issued in consideration of a growing number of road accidents due to stalled or parked vehicles on the streets and highways.