Several layers were examined as part of the highway improvement needs analysis conducted for the 2017 State Transportation Plan. Operation needs for the Interstate system were analyzed through the Infrastructure Condition Evaluation-Operations (ICE-OPS) tool. The Interstate system was divided into 54 corridors, and ICE-OPS provided a composite rating for each corridor based on normalizing and weighting nine operations-oriented criteria. (Note: Since the adoption of the State Transportation Plan, another 85 non-interstate corridors were also analyzed and added to this layer.) Corridors were then ranked based on their composite scores. For more information, see iowadot.gov/iowainmotion.