SR 17's combination of narrow shoulders, dense traffic, sharp turns, blind curves, wandering fauna such as deer and mountain lions, and sudden changes in traffic speeds have led to a number of collisions and fatalities, leading to the reputation of SR 17 as one of the most dangerous highways in the state. In the winter months, because SR 17 crosses a high precipitation area in the Santa Cruz Mountains, the roadway can become slippery from rain, snow or ice, especially at the summit.