The authority said the speed limit on the Sychnant Pass should be cut from 60 to 40 mph, and hazard signs used.
Horse riders and farmers have called the road a "dangerous rat run".
The council also expressed concern about "a lack of information" from the Welsh Government about roadworks on the A55.
It said the works could lead to more cars using the pass, which would further compromise safety.
The Conwy tunnel has been reduced to one lane for three weeks from 14 February as part of improvement works.
The authority are to write to the Welsh Government to request a "meaningful and ongoing dialogue" about the scheme.
It will also ask for more information on the economic impact of the roadworks, and for train operators to provide more services to tackle congestion.
The Welsh Government have been asked for comment.
Conwy council has agreed to improve safety on a mountain road after a horse was hit by a car and killed last year.