NHTSA announced today that it has denied a request by Bridgestone/Firestone Inc. to open a safety defect investigation into the handling and control characteristics of the Ford Explorer SUV following a tread separation of a rear tire. The decision followed an extensive analysis of agency data and information provided by Firestone and Ford. "The data does not support Firestone's contention that Explorers stand out from other SUVs with respect to its handling characteristics following a tread separation," said NHTSA administrator Jeffrey Runge. Firestone's request identified four findings based on tests of the control and stability characteristics of the Explorer and four other SUVs. Firestone provided its test data to NHTSA in several stages, with the last submission coming Dec. 4.