Montes, Elaine2020-01-212020-01-212019http://hdl.handle.net/1773/45022In September of 2015, the Washington State Department of Transportation (WSDOT) by approval of state legislature, opened the express toll lanes on the auxiliary highway known as Interstate 405 (I-405). Part of a master plan1 to improve one of Washington’s most congested highways2. WSDOT’s objective was to add a dynamic tolling system to improve commutes in both South and North directions of the highway3. In this paper, I will examine the efficiency4 of the I-405 High Occupancy Toll (HOT) lanes using commuter data provided by WSDOT for the year 2017-20185 through regression models I created. It is important to further investigate into the efficiency of tolling systems as it becomes more commonly utilized by several state departments of transportation across the United States as a method to moderate congestion. Through this analysis, I hope to add additional information to help further develop an understanding and to provide feedback on its efficiency. The current HOT pricing model is guided by a mathematical algorithm that manages toll rates from real time traffic and updates every ten minutes with a maximum charge of $10. Although this analysis requires additional future research, I concluded that the I-405 HOT lanes have not been operating above forty-five miles per hour ninety percent of the time during the peak hours that it was required to be according to the Revised Code of Washington 47.56.880. As a result, there appears to be little differentiation from the HOT lanes to the general-purpose lanes in terms of congestion moderation.en