Browsing by Author "Corbett, Michael"

Now showing 1 - 4 of 4
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    Benefit-Cost Analysis for Intersection Decision Support
    (Minnesota Department of Transportation, 2007-10) Corbett, Michael; Levinson, David; Zou, Xi
    The Intersection Decision Support (IDS) system is designed to assist drivers on stop-controlled low-volume rural roads choosing gaps when confronted with busy multiple lane divided-highways, without affecting traffic on the high-volume road. The hope is, that by providing better gap guidance, fewer crashes (and fatalities) will occur. This research develops a framework for analyzing such a new, and presently under-specified technology, and illustrates that framework by comparing that with more conventional engineering approaches, as well as a "do-nothing" base case. The results show that the IDS System may be an effective tool to reduce crash rates at various intersections. More research is needed to address reliability and stability issues, and in determining how cost- effective of a solution the IDS System is compared to other "traditional" alternatives.
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    Benefit-Cost Analysis of Spring Weight Restrictions in Lyon County, Minnesota
    (2004) Ning, Li; Levinson, David M; Smalkoski, Brian; Corbett, Michael
    Spring Weight Restrictions (SWR) forbid heavy trucks to run on some low- level roads during the spring thaw period. There has been long dispute between trucking industry and road agencies on the effectiveness of this policy. Previous studies showed inconsistent results on this issue. This paper consistently estimates the benefits and costs of the SWR policy in Lyon County, Minnesota. A freight demand model was built to simulate truck flow on the road network. A pavement performance model estimates pavement life in terms of rutting failure based on the traffic provided by freight demand model. The analysis shows that the benefits of SWR to local agencies are exceeded by the costs to truckers, which suggests lifting these seasonal restrictions on 7 and 9-ton roads.
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    Evolution of the Second-Story City: The Minneapolis Skyway System
    (Pion, 2009) Corbett, Michael; Xie, Feng; Levinson, David M
    This paper describes and explains the growth of the Minneapolis Skyway network. Accessibility is used as a major factor in understanding that growth (i.e. does the network connect to the location(s) with the highest accessibility, followed by the second highest, and so on). First, employment opportunities are used as the measure of activity and are based off of the square footage of buildings and/or ITE trip generation rates. Using information about the buildings located downtown for each year since the first skyway was built, the accessibilities of each of the connected and adjacent unconnected blocks were calculated for every time period the skyway system expanded. The purpose is to determine how often the expansion connected the block with the highest accessibility. The results show that though important, accessibility was rarely maximized, except in the early stages of development. A connect-choice logit model relating the probability of joining the network (in a given year) to accessibility and network size was employed. The results show accessibility does remain an important factor in predicting which links are connected. Physical difficulties in making connections may have played a role, as well as the potential for adverse economic impacts.
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    Operating Costs for Truck
    (2004) Levinson, David M; Corbett, Michael; Hashami, Maryam
    This study estimates the operating costs for commercial vehicle operators in Minnesota. A survey of firms that undertake commercial truck road movements was performed. The average operating cost per kilometer for commercial vehicle operators was calculated from the survey responses. Results show that the translog and Cobb-Douglas models have approximately equal explanatory power in estimating the total cost from the data. The models also revealed the presence of nearly constant returns to scale, a finding consistent with earlier studies; an increase in output (total truckloads) of 1% increases total costs by 1.04%.