This is the Most Dangerous Road in Idaho Idaho's terrain inevitably creates some dangerous roads for drivers. According to the Advocates Injury Attorneys, Idaho is about to hit an all-time high in traffic-related fatalities. There are some roads and highways specifically in the Gem State to use extra caution when driving on due to their notorious conditions. As it turns out the most dangerous road in Idaho isn't a rocky backroad or anything; it happens to be US-95 which is ranked as one of the worst highways in the entire country. US-95 has seen a rapid increase in the annual number of fatal car accidents over the last few years. In just the last decade alone, US-95 has seen over 140 fatal crashes.