i-394 mnpass technical evaluation preliminary findings march 23, 2006 doug sallman – cambridge...

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?