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This report contains data regarding the wear and tear caused by friction on various Minnesota highways in 1990. Included are: Interstate 35, TH 169, TH 212, TH 61, TH 316, TH 194, TH 21, and TH 36.

Dynamically priced High Occupancy Toll (HOT) lanes have been recently added to the traffic operations arsenal in an attempt to preserve infrastructure investment in the future by maintaining a control on demand. This study focuses on the operational and design features of HOT lanes. HOT lanes' mobility and safety are contingent on the design of zones ("gates") that drivers use to merge in or out of the facility. Existing methodologies for the design of access zones are limited to engineering judgment or studies that take into consideration undersized amount of observations. Case in point is the fact that the design philosophes between the two HOT facilities in Minnesota are diametrically opposed. Specifically, the I-394 freeway, the first dynamically priced HOT lane, was designed with a closed access philosophy, meaning that for the greater length of the roadway access to the HOT lane is restricted with only specific short-length sections where access is allowed. In contrast I-35W, the second HOT corridor, was designed with an open access philosophy where lane changes between the HOT and the GPLs are allowed everywhere except for a few specific locations. This contradiction generated questions as to effect each case has on safety and mobility. This study presents an assessment of safety and mobility on the two facilities as they operate today and highlights the issues present on either design.

While High Occupancy Vehicle (HOV) lanes have been used for decades as a strategy for mitigating congestion, research has shown that they are not always effective. A 2001 study of the I-394 and I-35W HOV lanes in Minnesota found that the HOV lanes were on average underutilized, moving fewer people than the General-Purpose Lanes (GPL) even with the increased number of passengers per vehicle. To address the issue of underuse, in 2003 the Minnesota Legislature authorized the conversion of the I-394 HOV lanes into High-Occupancy Toll (HOT) lanes, named the MnPASS Express Lanes. The MnPASS lanes operate using a fully dynamic pricing schedule, where pricing is dictated by the level of congestion in the HOT lane. To better understand the nature of HOT lanes and the decisions of their users, this study explored the possibilities for a microscopic traffic simulation-based model of HOT lanes. Based on a series of field studies where the price of the toll was changed while observing changes in demand in the HOT lane, models describing the lane choice behavior of MnPASS users were developed and calibrated. These models interfaced with the traffic simulation software Aimsun through a number of extension modules and tested on the two MnPASS corridors of I-394 and I35W corridors in the west and south suburbs of Minneapolis, Minnesota. The integrated HOT simulation tool was also used to develop and test a number of alternative pricing strategies including a more efficient version of the current strategy.

The District 3 I-94 and District 6 I-35 Alternate Route Signing Final Report chronicles the process of developing an alternate route system for interstate corridors. Major delays and roadway closures occur along the Interstate system as various incidents occur on the roadway. These incidents require cooperation between MnDOT, Minnesota State Patrol, and local first responders to respond to the scene and manage Interstate traffic until the corridor can be opened. These alternate routes provide guidance to first responders and MnDOT staff should an incident occur. Alternate route systems were developed for the I-94 corridor through District 3 and the I-35 corridor through District 6. The process used in developing these alternate routes is transferable to other corridors throughout the State. This research project includes the route development process and the development of two final deliverables for use by MnDOT Districts and local stakeholders. The process of developing alternate routes required field review exercises and input from the project's Technical Advisory Panel and other local stakeholders. The project resulted in the development of an Alternate Route Operations Guide and a Signing Plan. The Alternate Route Operations Guide is intended to provide a tool for first responders during an incident by providing suggested routes and temporary traffic control with an outline of the necessary actions for implementation. Suggested static signing locations are provided within the Signing Plans developed with the project.

On November 13, 2008, I reviewed the section of Interstate 35 southbound just north of junction with Interstate 90. The reason for reviewing this section is the following excerpted from report “Field Observations of the Coring of I-35 Between Mile Post 18 and 16 Southbound” Jerry Geib and Thomas Wood September 27, 2005. (Appendix A) This review is on going research to determine how Bituminous over Concrete (BOC) pavements crack, and how to reduce or eliminate cracking of the Hot Mix Asphalt (HMA) overlay.

This Technical Summary pertains to Report 2015-22, “MnPASS Modeling and Pricing Algorithm Enhancement,” published May 2015.

This Technical Summary pertains to Report 2014-23, “Evaluation of the Effect of MnPASS Lane Design on Mobility and Safety,” published June 2014.

This Technical Summary pertains to Report 2015-43, “I-94 and I-35 Alternate Route Signing,” published August 2015.