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The annual Congestion Study is a geographical illustration of the metropolitan freeway system's traffic performance. It portrays time and areas of congested traffic flow during the A.M. and P .M. peak periods. Congested areas are determined from data gathered by traffic management sensor arrays. The data, five-minute volumes and lane occupancy values, provide input into the determination of the average five-minute running speeds per lane. This report is a summary of the time a freeway operates below 45 miles per hour. Freeway system field observations indicate that under this condition, shock waves develop in the traffic flow. Our working definition of congestion is then traffic flow below 45 miles per hour. The data summary compares the traffic during the month of October in each of the years. This is done to minimize the effects of construction and maintenance-induced congestion and to account for school-induced traffic loads. The study uses 1993 as a base year, the first year the report was done.

This report presents data using multiple-choice questionnaires to learn how drivers respond to traffic information in the form of advisory messages. Two experiments, comprising 112 participants, were conducted using the same technique and yielding similar results. The traffic information messages presented to participants varied in three respects; quantitativeness of information, imperativeness of advice, and timeliness of information. Two additional factors were examined; the amount of traffic congestion stated to be directly observable on the route and the stated accuracy of messages received in the past. Results obtained from the questionnaires indicate that the structure of the traffic message did influence the driver behavior. The propensity to depart from the planned route ahead of schedule was greater when respondents had; few exit options remaining, been told traffic levels were high, received accurate traffic information in the past, and had received messages which contained quantitative and/or imperative information. Traffic controllers with this knowledge of driver behavior could act to further reduce trip times and congestion by using the control tools currently available to them. The major conclusion we can draw from this study is that when possible and appropriate, advisory messages should contain accurate, timely, quantitative and imperative information.

The purpose of this project, "Trucks and Twin Cities Traffic Management," is to identify strategies that will reduce congestion for trucks traveling within and through the Twin Cities. The planning and development of most highway facilities focuses on the general needs of the majority of traffic in the traffic stream. However, the performance, function, and purpose of heavy trucks are dissimilar to those of the majority of the vehicles in the traffic stream. It is for this reason that the National Cooperative Highway Research synthesis report 314 identified a number of improvements that state transportation agencies have implemented, or are planning to implement, that focus on the unique needs of trucks to better accommodate truck-borne freight traffic. Additionally, to help reduce delays and congestion a number of urban areas have conducted studies of the unique issues trucks face. The study first identified an exhaustive list of potentially feasible strategies and then through iterative steps narrowed these down to the most promising. Five strategies were ultimately selected. The report focuses on issues related to the five strategies and their implementation.

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.

The Integrated Corridor Management (ICM) approach has drawn increasingly more attention in recent years because it is believed to be a promising tool to mitigate urban traffic congestion. In this project, a maximum flow based control model was first developed to handle oversaturated traffic conditions at signalized arterials. Based on the arterial control model, an integrated control model was proposed to manage network congestion. Through diversion control, the model aims to fully utilize the available capacity along parallel routes. The impact of the diversion traffic is considered, especially for signalized arterials, so that traffic congestion on the diversion route can be reduced or eliminated by proper adjustment of signal timings. This model does not rely on time-dependent traffic demand as model inputs and it is ready to be implemented at typical parallel traffic corridors where the standard detection system is available. The performance of the proposed model was tested using microscopic traffic simulation in the I-394 and TH 55 corridor in Minneapolis, Minnesota. The results indicate that the proposed model can significantly reduce network congestion.

In this project, researchers sent mail surveys to commercial vehicle operators (CVOs)--for-hire carriers and private fleet operations-in the Twin Cities to determine their use of congestion information and their ability to attach specific values to congestion costs. The project also assessed the ability of CVOs to avoid congestion. The report presents survey findings. Despite the fact that a vast majority of respondents indicated congestion information would be useful, CVOs do not rely currently on available congestion information to any significant extent. The reasons may include lack of awareness and/or an inability of CVOs to effectively use the form and content of the information. For-hire carriers also are not well-equipped to estimate congestion costs with any degree of confidence. This results from apparently inadequate costing systems and/or technology to capture costs at the vehicle level. Further, respondents said that they had very little flexibility to adjust schedules to avoid congestion. Also, shippers without private fleets feel significantly less strongly about congestion as a problem than their counterparts with such fleets. Thus carriers maybe constrained in their ability to use congestion information. The report also contains a demographic profile of CVOs operating in the Twin Cities and recommendations for further research.

Traffic flow study of the Miller Hill corridor on Highway 194 between Arlington Avenue and Haines Road, the most heavily traveled and congested roadway in the Duluth area. The study includes preliminary data collection using a non-intrusive Remote Traffic Microwave Sensor (RTMS), traffic flow modeling, traffic simulation and development of an efficient traffic signa l light timing plan. The author develops a reasonably accurate model to estimate traffic flow, which is used in association with the RTMS and a database system to conduct real-time traffic simulations. Results of the simulation were used to develop a traffic-signal optimization plan with Synchro 5.0 software. Discussion of problems faced and how improvements could be made through further research. The author concludes with a proposal that recommends the adoption of the newly developed signal-timing plan to alleviate the traffic congestion on the Miller Hill corridor.

"What would it take to build our way out of congestion in the Twin Cities?" was the question posed by researchers five years ago. This previous study solved a roads-only network design problem (NDP) for the Twin Cities of Minnesota. Building on that work, another network design problem is examined for the Twin Cities metropolitan area of 3 million, to examine the tradeoff between demand side reductions and the limited access capacity expansion necessary to achieve desired levels of service. The problem is simplified by pre-determining a mode split, which allows for incorporating decreasing demand directly as an input rather than in the model formulation. The problem is solved using Sequential Linear Expansion (SLIE), a modified method of successive averages (MSA). Computation time for the large network is decreased to a reasonable length using another modification, the MSA with decreasing re-initialization (MSADR). A typical personal computer can solve this large-sized problem within 24 hours. For forecasted travel demand for 2030, it was found that if the number of trips were reduced by 20%, lanemiles needed to achieve LOS D decreases by up to 43%.

The Minnesota Department of Transportation (Mn/DOT) collaborates with Team Transit to increase transit use and improve the efficiency of the metropolitan highway system by allowing buses to use the designated shoulders to bypass traffic congestion. In this project, researchers evaluated the costs and benefits associated with bus-only shoulder projects and concluded the following: • Measured travel time savings on the bus-only shoulders are highly variable, but savings run as high as nine minutes per trip under snowy conditions. • 60 percent of respondents indicated that, on a typical day, the use of shoulders by buses resulted in travel time savings of about 5 minutes. • Bus regard bus-only shoulders as a use and positive addition to their commute trip. • The number of accidents directly relating to bus use of shoulders is very low. • The 10-foot minimum requirement for bus-only shoulders is marginally adequate. The study concluded that the use of the bus-only shoulder concept should continue, with an evaluation of additional projects on a case-by-case basis. The report also presents additional suggestions regarding guidelines and criteria for projects. This report is unpublished. 15 copies were produced and distributed.

The Tipping Point – What COVID-19 Travel Reduction Tells Us About Effective Congestion Relief uses observed data collected before and during the COVID-19 pandemic in the Twin Cities metropolitan area to answer a question with important implications for highway investment planning and travel demand management: At what level of vehicle miles traveled (VMT) does congestion significantly decline or disappear? The study pursues this question through a series of statistical analyses identifying inflection points in the relationship between regional VMT and congestion. The study also looks at the relationship between VMT and congestion at the corridor level to assess the sensitivity of congestion on specific roadways to changes in travel demand. This analysis categorizes Twin Cities freeways based on congestion frequency, highlighting the corridors expected to become congestion free as VMT declines and the corridors expected to remain congested.