Comparison of travel time estimation using shockwave analysis and queuing theory to field data along freeways

There are several methods available for analyzing freeway bottlenecks, including shockwave analysis, and queuing theory. Even though the two methods are interrelated, previous research has concluded that shockwave and queuing theory are fundamentally different in calculating travel time and delay, while others have shown that the results from the two methods are the same. The objective is to compare travel time estimation using two analytical methods to field-measured travel times. Flow and speed data in one-minute intervals were collected along two freeway sections in Philadelphia, PA. Travel times were collected by tracking unique vehicles along these sections. Results showed that for section 1, travel time using both queuing theory and shockwave analysis was underestimated compared to the field-measured travel time. For section 2 the estimated travel time was similar to the field-measured travel time.