Summary: A novel procedure was developed and validated for the accurate observation of naturalistic driver gap acceptance behavior at unsignalized intersections. Specifically, two-way stop-controlled intersections with a two way left turn lane (TWLTL) on the major road were examined. Three intersections were included as experimental locations. A sample size was collected of approximately 875 minor street vehicles which were exposed to over 2400 individual gaps. Characteristics such as gender, approximate age, vehicle type, presence of a queue behind the lead vehicle, and presence of passengers in the vehicle were collected as a function of the time of day (TOD). This work provides updated measures for the accepted gap as TOD varies, as well as exploring how accepted gaps are related to the wait time of a vehicle at the stop line.