Once the expressway was opened, throngs of people took the trip through to Ilan, and this massive popularity saw as many as 34,000 cars traveling through each day, rising to 50,000 at the weekends, leading to many people's first impression of the expressway being one of traffic jams.
北宜高全線通車，許多民眾搶在 9 月底收通行費之前慕名一遊，帶動人氣沸騰，每日車流量都接近 3 萬 4 千輛的上限，遇到週休假日，更直逼 5 萬大關，「塞爆了！」成為民眾對北宜高的第一印象。