No.
'Narrower' is in comparative adjective form, e.g. "This hallway is narrower than the others".
The adverb form would be 'narrowly', e.g. "the train narrowly missed the man by the rails".
The road is narrower ahead. The road is narrower ahead. The road is narrower ahead.
narrow is narrower than broad because it is.
taxonomy
narrower. The new Fords are narrower than the old models.
The usual antonym of narrower is "wider."
Why some drugs have narrower spectrum than others
Traffic lanes are narrower on the north east coast because they were constructed in to be that way.
narrower and narrowest
Narrow, narrower, narrowest.
Taper
Narrow, narrower, narrowest.
narrower, narrowest