What Drives Decisions of Single-Occupant Travelers in High-Occupancy Vehicle Lanes? Investigation Using Archived Traffic and Tolling Data from MnPASS Express Lanes

The HOT lanes concept relies on the assumption that SOVs will be discouraged from entering HOT lanes as toll rates increase, thus preventing HOT lanes from becoming congested. Most willingnessto-pay research has either focused on stated preference (SP) surveys (3) or investigated the median cost per hour of commute time saved (4). Although SP studies have been shown to be inaccurate in determining real-world HOT lane behavior (4), little research has been conducted to analyze and model actual drivers’ responses to minuteto-minute changes in toll rates and traffic conditions by using empirical data from an operational HOT lane system. This paper attempts to understand and model the impact of toll rates and traffic conditions on the behavior of drivers of SOVs in a HOT lane system through analysis of data from an operating HOT lane facility in Minneapolis, Minnesota. This is necessary to make maximum use of this ATM strategy: allowing road operators full understanding of the impact of toll increases on traffic assignment. HOT lane usage is measured from a combination of toll transaction records and detector data from the I-394 MnPASS express lane system. The study period was the morning peak between November 7, 2006, and March 31, 2008, along the 2.7-mi, barrier-separated, reversible section of I-394 near downtown Minneapolis. The study ignores the possibility of SOVs using the system illegally on the basis of the low 3% noncompliance rate found for the section in a 2006 study (5).