I-394 MnPASS Technical EvaluationPreliminary FindingsPreliminary Findings
March 23, 2006March 23, 2006
Doug Sallman – Cambridge Systematics, Inc.Doug Sallman – Cambridge Systematics, Inc.
Overview• Evaluation Objectives
•Evaluation Challenges
•Evaluation Approach
•Preliminary Findings
•Next Steps
Objectives• Conduct an independent assessment of
the performance impacts resulting from the I-394 MnPASS deployment including:– Travel times/speeds– Vehicle and person throughput– Safety– Noise and emissions
• Investigate other issues including transit operations, enforcement and revenue
Approach• Collect data representing a broad period
before and after to control for: – Traffic growth trends– Cyclical variations (day-of-week, time-of-year)– Weather conditions– Incident occurrence– Other external factors
• Compare performance from like periods with and without MnPASS to isolate any changes
Challenges• MnPASS system itself is dynamic
• Hours of operation change
• Construction of auxiliary lane in the westbound direction
• Closure of I-494 to I-394 ramps
• Record high fuel prices
• Changes to transit routes and fares
Preliminary Findings• Interim performance evaluation
focuses on the period from June to December 2005– Does not include data from the initial
period of 24/7 operation
Preliminary FindingsVolumes/Throughput
Volume/Throughput• Regional automobile travel demand
has decreased compared to previous years, unrelated to MnPASS– Nearly 2% decrease in peak hour
volumes on I-35W
Volume/Throughput• I-394 MnPASS lanes peak hour
volumes increased 9 to 33%
• Total I-394 peak hour roadway volumes increased by up to 5%
• Volume changes on the fringes of MnPASS operational hours were less positive or lower
Preliminary Findings Speeds
Vehicle Speeds• Despite increase in volume, speeds
in the MnPASS lane have not decreased
• Travel speeds in the general purpose lanes increased by 2 to 15 percent– The relative speed change is most
significant when conditions are most congested
Preliminary Findings Safety
Preliminary Findings Safety
• Time lag in collecting crash data does not yet allow for statistical analysis of safety impacts
• Anecdotal information and informal review of MnDOT’s incident log suggests no negative impact
Preliminary Findings Enforcement
Preliminary Findings Enforcement
• Over 3,300 stops were made by enforcement officers on the I-394 corridor
• 50% of stops involved HOV or double white line crossing violations
Preliminary Findings Enforcement
• Violation rates have dropped at nearly all I-394 locations
• Violation rates on I-394 are much lower than on I-35W
Preliminary Findings Noise and Emissions
• MnDOT conducted monitoring and analysis has revealed no noise or emissions impacts
Preliminary Findings Use and Revenue
• Use and revenue have increased steadily
• Number of transponders has increased from 5,650 to over 9,000– Continues to increase at 3% growth
• Average owner uses the MnPASS lane twice a week
Preliminary Findings Use and Revenue
• Over 500,000 tolls were paid in 2005 resulting in $350,000 in toll revenue
Next Steps• Additional field data collection planned for
Spring to better assess carpool impacts
• Interviews with transit operators
• Continue to collect and analyze automated data through July
• Assessment of safety issues
• Final Evaluation Report due in August
Questions?