Road hazards are a subject that has been discussed often on this site, as such road hazards can be hazardous to motorists and motorcyclists. Road hazards can take many forms, including items that are sitting on the roadway or are falling off of other vehicles. These items, including deer running across the roadway, often are unexpected and pose a challenge to drivers who are seeking to avoid hitting such objects.
As well, there are various types of road hazards relating to pavement deformities, including potholes, broken pavement, uneven pavement, large cracks, and gravel.
Many types of road hazards are further discussed on the DuPage County Road Hazards page.
One type of road hazard that is both unexpected and potentially (very) dangerous to motorists is that of buckling pavement. This typically happens during high outdoor temperatures, and typically involves a substantial, unforeseen “bump” forming on the roadway as the pavement breaks apart and rises. While this pavement buckling is rare, it does happen. One recent example in the Chicago area was seen on South Lake Shore Drive in July 2016, and is discussed in the July 12, 2016 CBS Chicago article (with video) titled “The Reason Lake Shore Drive Pavement Buckles.”
On July 20, 2016, the Illinois Department of Transportation (IDOT) issued a warning about pavement buckling, given that Chicago area weather (along with other weather in the region) is expected to climb well into the 90-100 degree range. The IDOT news release is titled “Extreme Heat Could Lead to Pavement Failures.” (pdf) An Excerpt from the release:
The Illinois Department of Transportation (IDOT) is urging motorists to be on the alert for the possibility of pavement buckling on roads throughout the state in the next few days due to the recent rainfall and extreme heat in the forecast. The combination of very high temperatures and precipitation can lead to pavement expanding and ultimately buckling or blowing out, causing uneven driving surfaces in some areas. As long as the heat and humidity persists, IDOT will be monitoring the situation, with crews available to make repairs as quickly as possible if they are needed.
Additional details regarding this possible pavement buckling can be seen in the IDOT and CBS Chicago sources mentioned above.