Experiences of NDDOT depoloyment of FAST on the Buxton Bridge and joint depolyment with Mn/DOT on Red River Bridge.
Fargo, North Dakota, United States
Cummings, North Dakota, United States
Evaluation of North Dakota's Fixed Automated Spray Technology Systems
Summary Information
North Dakota's winters are quite cold, with nearly 95 percent of days from November through March having low temperatures at or below 32 degrees Fahrenheit. These temperatures require application of anti-icing solution to the roadways in order to reduce the formation of frost and ice on the roadways, which is particularly likely on bridge decks. Two fixed automated spray technology (FAST) systems were installed on highways in North Dakota because of the high crash rates at the two locations. The Buxton Bridge FAST system became operational in December 2002, and the Red River Bridge FAST system came online in January 2007. The Buxton Bridge system covers 370 feet of roadway and bridge decking, while the North Dakota DOT-Minnesota DOT (NDDOT-Mn/DOT) jointly operated Red River Bridge system covers 2300 feet, with 1300 feet of that being bridge decking.
Data for twelve winter seasons from January 1, 1996 through May 31, 2008 were collected from NDDOT and Mn/DOT in order to analyze the effectiveness of the FAST systems. Crashes occurring between October 1st and April 1st are considered winter crashes. Crashes that had other contributing factors that could not be reduced by the use of a FAST system, such as collisions with deer or debris, were removed.
Findings
Buxton Bridge
Based on before and after crash data, the FAST system provided significant reduction in the number of crashes, with the average number of crashes per season dropping from 6.2 to 2.5 per season (59 percent). The number of crashes involving property damage were reduced by 54 percent, while crashes with personal injuries were reduced by 70 percent. When AADT is used to normalize the number of crashes, the FAST system provided a 66 percent reduction in crashes, with property damage crashes reduced by 62 percent and injury related crashes by 75 percent.
Red River Bridge - North Dakota Side
Based on before and after crash data, the FAST system provided significant reduction in the number of crashes, with the average number of crashes per season dropping from 6.1 to 3.2 per season (48 percent). The number of crashes involving property damage were reduced by 32 percent, while injury related crashes were eliminated. When AADT is used to normalize the crash data, the FAST system reduced total crashes by 55 percent, with property damage crashes being reduced by 43 percent.
Red River Bridge - Minnesota Side
Based on before and after crash data, the FAST system provided significant reduction in the number of crashes, with the average number of crashes per season dropping from 5.7 to 3.6 per season (37 percent). The number of crashes involving property damage were reduced by 46 percent, while non-incapacitating injury crashes were reduced by 37 percent. When AADT is used to normalize the crash data, the FAST system reduced total crashes by 46 percent, with property damage crashes being reduced by 53 percent and non-incapacitating injury crashes decreasing by 46 percent.
