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Speed Too Fast for Conditions (STFC) is a field provided on most agency crash forms. The intent is to label scenarios where a driver was traveling below the posted speed limit but the speed at the time of the crash was not appropriate for prevailing environmental conditions and was a contributor to the crash. However, significant variations exist in interpreting the definition of the environment when coding crash forms. As a result, it is often left to the attending officer's interpretation.
In Arizona, historically STFC was defined as “Traveling at a speed that was unsafe for the road, weather, traffic or other environmental conditions at the time.” In many cases, an officer would include the behavioral or human environment and could interpret driver incapacity (Driving Under the Influence (DUI), impaired, distracted, fatigued) as a condition that would warrant traveling at a lower speed regardless of actual roadway conditions. For instance, a drunk driver on dry daytime roads traveling under the speed limit could be coded as Speed Too Fast for Conditions if the officer felt the state of impairment warranted a lower speed. Depending on the attending officer’s interpretation, there may be scenarios in which no speed is safe for conditions1. While it is important to address these crashes, solutions should focus on the root cause of the crash when feasible. Countermeasures geared specifically towards speeding, such as Dynamic Speed Feedback Signs (DSFS), lane narrowing, or use of landscaping, may be less effective when the driver is impaired. Rather areas with a high number of impaired crashes should be targeted with countermeasures that address the impairment, such as enforcement.