Is disobeying traffic laws—such as slightly exceeding the speed limit without danger, or driving with an expired license, or parking in a prohibited spot without obstructing traffic—considered a sin for failing to obey those in authority, even if the violation is not caught?

Scholars have determined the obligation to abide by traffic laws and regulations because they are among the Masalih Mursalah (unrestricted public interests) that the Imam considers. Therefore, obedience to him in these matters is obligatory due to the presumed benefit in adhering to them and the expected harm when failing to do so. The criterion in all of this is the predominance of good judgment, and averting harm takes precedence over achieving benefit.

Adherence to these laws is obligatory, and it appears that one who violates them may incur sin and is liable if such violation results in harm to others.

Traffic violations differ in their ruling depending on the strength of the benefit and the likelihood of harm. Thus, excessive speeding and running a red light are not like driving without a license for someone who is proficient in driving, or with an expired license, or parking in a prohibited spot due to a narrow street; these latter cases do not reach the ruling of running a red light. The best course of action for a Muslim is to adhere to all of these regulations and not transgress them.