Truth and the Time to React

Captain Ed at Captain's Quarters has been following the story of the events surrounding an incident involving Italian journalist Giuliana Sgrena, whose car was fired upon as it approached a U.S. manned checkpoint near the Baghdad airport shortly after she was freed from being a hostage. The incident claimed the life of Italian intelligence officer Nicola Calipari.

Sgrena's account of the incident, in which she claimed that U.S. troops at the checkpoint deliberately fired upon the vehicle without warning, has not withstood inspection. A joint American-Italian investigation, as reported in the New York Post, has cleared the soldiers at the checkpoint of any wrongdoing, as they were found to have acted prudently in using force to stop Sgrena's vehicle.

Given Sgrena's claims regarding the speed at which her vehicle was traveling (she has claimed her car was traveling at 30 miles per hour), I thought it might be useful to create a calculator that would indicate the elapsed time from when the official report indicates that the soldiers at the checkpoint went from signalling the car to stop to using deadly force to stop the vehicle.

Car Speed
Input Data	Values
Speed of Car in Miles per Hour

Elapsed Time
Distance from Checkpoint: Timeline	Time (seconds)
130 Yards: Soldiers Flash Lights to Signal Car to Stop
90 Yards: Soldiers Fire Warning Shots
65 Yards: Soldiers Use Deadly Force to Stop Car
Total Elapsed Time from First Signal to Stop

The calculator above assumes the speed of the car is unchanged throughout the incident.

According to the Texas Education Agency's Driver Training and Education department, the average response time required for a sober individual to respond to an external signal requiring they brake is roughly 0.75 seconds. With this being the case, it's unlikely that Sgrena's account of the event is accurate.

Update (30 April 2005): Sgrena's claims regarding her vehicle's speed has been directly contradicted by U.S. satellite imagery (HT: Little Green Footballs.) With the evidence that the vehicle was traveling in excess of 60 miles per hour, the total time that the driver had to respond to signs and signals and begin braking is 2.22 seconds - still more than adequate time to have avoided the event's tragic consequences. P.S.: Of course, you wouldn't know any of this if you're subscribing to the Los Angeles Times - people, there are multiple reasons why you folks in L.A. should be subscribing to the Arizona Republic instead. Make the switch today....