The majority of Wrong-way Crashes (WWCs) involve a driver using an exit ramp to enter a highway. As highlighted by a number of WWCs in Florida this year, these crashes are severe and often fatal. WWCs frequently involve drivers impaired by drugs and/or alcohol, but there is also evidence that age-related perceptual and cognitive declines put older drivers at greater risk for this type of crash. The current proposal aims to use crash analysis, in addition to a human factors approach, to understand the factors related to WWCs in older drivers, and to evaluate the effectiveness of new and existing countermeasures to prevent WWCs. Proposed studies will complement a Florida Department of Transportation (FDOT) funded simulator study on effective WWC countermeasures and recent FDOT initiated efforts to understand WWC crashes in Florida. The aim of the existing FDOT project is largely focused on examining the impact of traditional wrong-way countermeasures (pavement markings, signs) on younger and older drivers within the driving simulator. However, ASAP funding will allow for the exploration of relatively new and novel WWC countermeasures, such as the benefit of flashing wrong-way signs, new sign messages, novel roadway geometries, and the combination of different countermeasures. These studies will aide in our understanding of the best practices to reduce wrong-way entries, with the ultimate goal of reducing WWCs for drivers of all ages.