Chuang, CaraThis thesis provides an overview of Traffic Management Initiatives (TMI) trends over the years 2009 through 2016, and serves to highlight similarities and differences between four restriction types: Miles-in-Trail (MIT) restrictions, Ground Delay Programs (GDP), Airspace Flow Programs (AFP), and Ground Stops (GS). Yearly and regional patterns are investigated to find temporal and geographic tendencies, which are then compared across restriction types. We use various metrics of severity, which help explore TMI implementation methodology. This research confirms that the causal factors of TMIs are tied closely to their purposes and their locations within the National Airspace System (NAS). Finally, we suggest a method for matching restrictions based on common facilities and overlapping implementation time in order to determine the frequency of concurrent TMIs. The statistics presented in this thesis are meant to supply a “big picture” summary of restrictions implemented in the National Airspace using data recorded in the National Traffic Management Log (NTML).enThesisTransportationCivil engineeringHistorical trendsMiles-in-TrailNational Traffic Management LogSummary statisticsTraffic Management Initiatives