First responders assess a Nuclear/Radiological (NUCRAD) event in a timely and accurate manner by creating a site characterization that reflects the location of various levels of contamination based on their instruments' readings. The survey team experiences difficulty in accurately recording this critical data due to the challenge of operating multiple devices and communicating the devices' readings to other survey members. First responders produce a representation of the contamination or activity on a map that contain rings outlining the levels of activity and/or single locations of a single activity. Recently, several agencies began creating software programs that record a first responder's instrument readings, time, and the global positioning system (GPS) location plotting the information in real-time. The Environmental Protection Agency (EPA) Region 5 developed the Rapid Assessment Tool (RAT). This research evaluates the effectiveness of RAT by comparing the timeliness and accuracy of the site characterization created by multiple survey teams (one team not using RAT and another team using RAT). All of the Bioenvironmental Engineer (BEE) Survey Teams using RAT decreased their survey times for all scenarios. The Weapons of Mass Destruction - Civil Support Team (WMD-CST) survey teams using RAT decreased their survey times during the lane, bounce and bypass, star, and cloverleaf scenarios. However, survey times increased for the zigzag and radial scenarios.