Wa alaikum assalam.
Yes, it is permissible to walk in front of one’s father. The report in Al-Adab al-Mufrad (no. 44) is about adab (good manners), not about halal and haram. It encourages extra respect and humility toward parents, but it does not make everyday actions sinful.
The key point is intention and context. If someone deliberately walks ahead in a way that shows arrogance, disregard, or disrespect, then that contradicts good manners. But walking ahead due to normal routines—such as opening a door, leading the way in a crowded place, going first out of necessity, habit, or practicality—is completely fine and carries no sin.
Islam does not turn daily life into a constant moral trap. The Qur’an and Sunnah emphasize kind speech, gentleness, care, and respect, not rigid physical positioning. Parents themselves would not expect their children to freeze behind them at all times. Good character is shown through attitude, tone, and behavior, not by over-literalizing etiquette reports.
So, the narration teaches ideal conduct, not a strict rule. Practicing it when natural is good adab; not practicing it in routine situations is not sinful. Islam prioritizes ease, balance, and lived respect—not unnecessary burden.
JazakAllahu khairan.