摘要 :
Recently, attention has been directed towards the urban arterial street system toprovide greater mobility, specifically in the form of a network of high-mobility arterial streets. These streets were named stra tegic arterials and ...
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Recently, attention has been directed towards the urban arterial street system toprovide greater mobility, specifically in the form of a network of high-mobility arterial streets. These streets were named stra tegic arterials and would operate with greater capacity and operating speeds than current principal arterials, however, they would not fulfill the strict requirements of a freeway in terms of access control or right-of-way needs. Planning analyses demonstrated that capacity of the streets was the primary factor in causing diversion from a freeway system to strategic arterial system. Design features associated with a strategic arterial should be different from ordinary arterial streets and identifiable by the motorist as being different. Several design criteria were identified. At-grade only improvements for a case study on an existing arterial resulted in limited increases in speed due to the highly congested nature of the area. Grade-separated improvements were needed to generate a speed that is near freeway speeds. A benefit/cost analysis of improving a 4-lane, urban city street to either a 6-lane, urban city street or a 6-lane strategic arterial demonstrated that the higher quality facility, even though more expensive, is a better investment. Implementation of strategic arterials will require strong local jurisdictional support, which will play a major role in the successful implementation of a strategic arterial network.
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This report presents an analysis of HOV improvements for two signalized arterials in the Seattle metropolitan area. The first involves a planned 1,000 foot queue jumper lane on NE Pacific St. in the University District of Seattle....
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This report presents an analysis of HOV improvements for two signalized arterials in the Seattle metropolitan area. The first involves a planned 1,000 foot queue jumper lane on NE Pacific St. in the University District of Seattle. This planned improvement was studied prior to its implementation in Spring of 1990. As part of this study, an extensive before-data set was developed. The planned improvement in now in place, and an extensive after-study is now in progress as part of a follow-up project. The second study was more of a feasibility analysis of possible HOV improvements for a suburan arterial. Specifically, NE 85/Redmond Way, a 2.5 mile stretch of arterial for Interstate 405 in Kirkland to Willows Road in Redmond, was identified as one of the highest priority arterials to be considered for HOV improvements.
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The principal aims of the research project were: To determine saturation flowrates for an urban arterial under icy conditions. The measurement of startup lost times, were also included; To determine an optimal signal timing plan f...
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The principal aims of the research project were: To determine saturation flowrates for an urban arterial under icy conditions. The measurement of startup lost times, were also included; To determine an optimal signal timing plan for an urban arterial using the saturation flow rates and start-up lost times obtained under icy conditions; To compare the signal timing plan developed for icy conditions with a plan developed for the same arterial but using saturation flow rates and start-up lost times for dry, bare pavement conditions.
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The objectives of the study were to propose warranting conditions, to identify operational considerations and to prepare implementation guidelines for the development of flyovers. Also, it has been demonstrated that flyovers can i...
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The objectives of the study were to propose warranting conditions, to identify operational considerations and to prepare implementation guidelines for the development of flyovers. Also, it has been demonstrated that flyovers can increase the capacity of congested arterial intersections in a cost effective manner.
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The Florida Department of Transportation has released a report that explores ways to enhance the state's current freeway travel time reliability method, develops a new arterial travel time reliability method, and proposes a framew...
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The Florida Department of Transportation has released a report that explores ways to enhance the state's current freeway travel time reliability method, develops a new arterial travel time reliability method, and proposes a framework for considering travel time in a multimodal context.
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The addition of interchanges, traffic signals, or unsignalized driveways to an arterial corridor can increase crash risk and reduce travel speeds for vehicles using the roadway. As vacant land adjacent to a corridor is developed, ...
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The addition of interchanges, traffic signals, or unsignalized driveways to an arterial corridor can increase crash risk and reduce travel speeds for vehicles using the roadway. As vacant land adjacent to a corridor is developed, however, private landowners often show a strong interest in having a direct access point to the arterial route. Because the Virginia Department of Transportation (VDOT) has the authority to allow such direct accesses provided there is no immediate adverse impact, arterials in high-growth areas tend to show an increasing number of traffic signals as demands for direct access arise. In terms of long-range planning, it is practically difficult for the Commonwealth Transportation Board (CTB) to mandate that an arterial have a restricted number of access points since a subsequent CTB retains the ability to relieve such a mandate. This study investigated the feasibility of using the National Environmental Policy Act (NEPA) to make adding direct access points to a corridor more difficult. The study found that under some circumstances, NEPA can help protect the mobility and safety of a corridor through making it more difficult, but not impossible, to add access points. Specifically, NEPA can be used to help protect a corridor through four administrative mechanisms: (1) including the limited access requirement as a condition in the record of decision; (2) effecting a contract between VDOT and the Federal Highway Administration, known as the Federal-Aid Project Agreement, that stipulates limiting access as a requirement; (3) implementing a supplemental agreement between VDOT and interested parties that indicates how the character of the corridor shall be maintained; and (4) documenting the corridor-preservation conditions that remove the requirement that a project have an Environmental Impact Statement.
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This report documents the results of research conducted in a two-year TxDOT project dealing with the coordination of traffic signals on signalized arterials. This TxDOT project had two primary research objectives. The first object...
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This report documents the results of research conducted in a two-year TxDOT project dealing with the coordination of traffic signals on signalized arterials. This TxDOT project had two primary research objectives. The first objective was to develop guidelines for selecting software for use in signal timing projects. In order to achieve this objective, the researchers compared three popular signal timing optimization programs. These programs are Synchro, TRANSYT 7F, and PASSER II. The comparison was performed using several real arterials. The second objective of the project was to develop an enhanced version of PASSER II. This objective was achieved by developing a new graphic user interface, by re-engineering the underlying technology used in PASSER II-90 for maximizing arterial progression, and be developing a new delay estimation routine for undersaturated and oversaturated arterials. The new program has been named PASSER V-03. In addition to the above features, PASSER V provides several new models. These include: a genetic-algorithm-based optimizer for timing signals for optimum delay or progression, a re-engineered version of PASSER III technology for timing diamond interchanges using a single controller, and a tool for locating potential bottlenecks and for determining maximum throughput capacity of network.
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The purpose of this research study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severi...
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The purpose of this research study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severity of these accidents. Accident, geometric, traffic control, and volume data were collected and analyzed for 8,678 one-tenth-mile (0.16-km) roadway segments located in 19 metropolitan areas. The result of the analyses provides further evidence that specific geometric, traffic control, volume, and environmental conditions influence accident frequency and rate on urban roadways. Guidelines that can be used to identify accident problems and to select countermeasures are provided in this report. One important product of this research was the development of a comprehensive computerized accident and roadway data base that can be used to explore in greater detail specific urban arterial accident problems and possible solutions.
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The purpose of this study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severity of the...
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The purpose of this study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severity of these accidents. The report will be of interest to state and local highway officials involved in safety and traffic operations on urban roadways.
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The purpose of this study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severity of the...
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The purpose of this study was to examine the specific characteristics of urban arterial traffic accidents, and to identify general causal elements and related countermeasures that can be used to reduce the rate and severity of these accidents. The report will be of interest to state and local highway officials involved in safety and traffic operations on urban roadways. The results of the study provide further evidence that geometric, traffic control, volume, and environmental conditions influence the accident frequency and rate on urban roadways. Guidelines that can be used to identify accident related problems and to select appropriate countermeasures are provided in the report.
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