Background: Approximately twenty-five years ago, RIDOT stopped using granite curbing as a. standard, with the exception of bridge projects. The primary motivation was cost, as precast. concrete, the replacement, was cheaper to purchase and install.
Longest damage path and duration: The Tri-State Tornado. The longest recorded tornado journey in U.S. history was the Tri-State Tornado of 1925, which traveled almost 220 miles across southeastern Missouri, southern Illinois, and southwestern Indiana during its 3.5-hour life. The average tornado travels about 5 miles.
The mean number of tornado fatalities per year (over the past 30 years) in Illinois is between 2 and 3. However, death tolls vary significantly from year to year. Some year in â¦ Illinois see no tornado fatalities, while in 1990 a single tornado in Illinois killed 29 people. 5 people found this useful.