Download or read book A Study of Traffic Operations on Restricted Truck Lanes on Interstate Highways in Virginia written by Jennifer L. Peek and published by . This book was released on 1998 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Simulation Analysis of Traffic Flow Elements for Restricted Truck Lanes on Interstate Highways in Virginia written by Lester A. Hoel and published by . This book was released on 1999 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, increases in truck traffic on Virginia's highways have raised issues concerning safety and capacity on interstates such as I-81 and I-95. Lane restrictions represent a strategy that is intended to reduce conflicts between trucks and cars and facilitate traffic flow. Field experiments to determine the effects on existing traffic under lane restrictions for an interstate freeway segment are usually not feasible, and an alternative approach was selected. In this study, the simulation model FRESIM was used to estimate various traffic flow elements. The purpose of this study was to analyze changes in traffic flow elements (density, lane changes per vehicle, and speed differential) under conditions of restricted and unrestricted truck lane configurations. Prior to application of the simulation model to actual sites in Virginia, a scenario analysis was completed. The scenario analysis tested the variability of each traffic flow element considering the following variables: traffic volume, percentage of trucks, percentage of total volume by lane, presence or absence of lane restrictions, and grade. A statistical paired-sample t test was used to determine significant differences in the values of the three traffic flow elements when lane restrictions were applied. An analysis was also completed for three case studies in Virginia, located on I-81 near Buchanan, Christiansburg, and Wytheville. Two types of restrictions were tested: restricting trucks from the left lane and restricting trucks from the right lane. From the results obtained in this study several conclusions were drawn: (1) restricting trucks from the left lane with steep grades causes an increase in speed differential and may decrease density and the number of lane changes, (2) restricting trucks from the right lane causes an increase in the number of lane changes, and (3) site characteristics dictate the effects of truck lane restrictions. Based on the results of this study, it is recommended that (1) trucks be restricted from the left lane when grades are 4 percent or greater and (2) trucks not be restricted from the right lane. The study results did not support removal of truck lane restrictions in Virginia.
Download or read book Evaluation of Truck Lane Restrictions in Virginia written by Michael D. Fontaine and published by . This book was released on 2009 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virginia, like many other states, has used truck lane restrictions on parts of its interstate system in an attempt to improve mobility and safety. The Code of Virginia currently specifies two types of lane restrictions. First, trucks may not travel in the left-most lane of interstates with three or more lanes by direction (1) when the speed limit is 65 mph or higher, (2) along all of I-81, and (3) along interstates in the Virginia Department of Transportation's (VDOT) Northern Virginia District. Second, trucks may not travel in the left lane of two-lane directional interstate segments when their speed is below the posted speed limit; this restriction was enacted in 2007 and was intended to reduce cases of trucks impeding traffic flow on steep grades in the western part of the state. This report describes Phase II of a 2007 study that found that the safety impact of the first type of restriction appeared to be affected by traffic volume. Safety was enhanced on low- volume roads (i.e., annual average daily traffic [AADT] less than 10,000 vehicles per day per lane [vpdpl]) but degraded on high-volume roads (i.e., AADT above 10,000 vpdpl). Given that most of the high-volume interstates investigated were in Northern Virginia, there was a need to re-examine the safety analysis to ensure that the findings were not a product of the growing congestion in the region but rather were attributable to the effects of the truck lane restrictions. The purpose of this study was to provide a detailed assessment of the safety and mobility impacts of Virginia's truck lane restrictions, expanding on the Phase I study. First, crashes on high-volume interstates with three or more lanes by direction noted in the Phase I study were re-examined. Individual crash reports were reviewed, and any crashes that were not influenced by the restriction were removed from subsequent analysis. An empirical Bayes analysis was then used to re-assess safety using the screened crashes. Second, the operational and safety impacts of the restriction on two-lane segments of interstate were examined. Third, the effect of an enforcement campaign on compliance with the restriction for two-lane segments was determined. The crash analysis for the high-volume, three-lane segments confirmed that crashes were higher than expected after the restriction was put in place and thus were not merely the products of growing congestion. The safety and operational impacts of the restriction for two-lane interstates revealed no significant benefits, likely because the level of non-compliance with the restriction was high. With regard to the effect of the concentrated enforcement campaign, compliance improved, but the improvement was relatively modest. The study recommends that VDOT (1) pursue a legislative modification to remove truck lane restrictions on high-volume interstates with three or more lanes in each direction; (2) determine if signing could be modified to improve compliance; (3) partner with the Virginia State Police and the Virginia Trucking Association to increase compliance on the two-lane directional segments of interstate; and (4) direct a study to re-evaluate the effectiveness of the two-lane restrictions once at least 3 years of "after" crash data are available. Removal of the truck restrictions on the specified high-volume interstates should create crash reduction benefits. If crash costs are converted into dollars, an estimated $266,996 of crashes would be eliminated statewide annually through removal of these restrictions. Those costs accrue to drivers. Additional direct savings to VDOT would occur through the reduction of signing.
Download or read book Exclusive Lanes for Trucks and Passenger Vehicles on Interstate Highways in Virginia written by Lester A. Hoel and published by . This book was released on 1997 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increases in heavy truck traffic on Virginia's highways in recent years have raised concerns about both safety and capacity, particularly on the interstate system. Transportation agencies have developed a number of strategies for dealing with the impacts on safety and capacity of a truck population that has been increasing in volume and in the percentage of large tractor-trailers. One strategy that has been suggested is separate lanes for trucks and passenger vehicles. A reliable methodology to determine when separate lanes for trucks and passenger vehicles are economically feasible would enable transportation officials to make informed decisions concerning when this approach should be considered and used. This study evaluated a computer program, Exclusive Vehicles Facilities (EVFS), developed by the Federal Highway Administration for determining the economic feasibility of separating trucks and other vehicles on freeway segments. A 50.7-km (31.5-mi) segment of 1-81 in Virginia was selected to demonstrate the application of the program. A number of factors contribute to the feasibility of exclusive lanes. Although no single factor predominates, traffic volume, vehicle mix percentage, accident rates, and maintenance and construction costs are given more weight than other factors in the program. Among the program's strengths are its ability to analyze a number of alternatives for a variety of different conditions, its ease of use, and the fact that it can be inexpensively applied. Its weaknesses include its inability to differentiate between the lane(s) (i.e., inside, middle, outside) to which restrictions are applied and its unsuitability for analyzing exclusive lane alternatives in which a barrier is used to separate vehicle types. With respect to 1-81, several exclusive lane strategies produced a benefit-cost ratio greater than 1.0 and a net present worth in the millions of dollars. Should 1-81 or another high-volume interstate corridor with a large truck percentage be considered for improvement, VDOT should apply EVFS to assist in evaluating the feasibility of exclusive lane alternatives. Since EVFS is designed to perform economic analyses, operational and geometric implications of any exclusive lane strategy should also be considered.
Download or read book Evaluation of Truck Lane Restrictions in Virginia written by Michael D. Fontaine and published by . This book was released on 2007 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: A number of states have implemented truck lane restrictions in an attempt to improve safety and mobility on freeways. These restrictions typically prohibit trucks from traveling in the median lane, potentially increasing passing opportunities and reducing negative interactions between slow-moving trucks and other vehicles. Virginia currently has two forms of truck restrictions in place. The first type of restriction prohibits trucks from the median lane of interstates that have three or more lanes by direction, provided certain criteria on speed limit and location are satisfied. The second type of restriction prohibits trucks from traveling more than 15 mph below the posted speed limit in the left lane of two-lane directional interstate segments. This report documents the results of a safety and operational evaluation of Virginia's truck lane restrictions. Crash data were examined at a total of 43 sites with restrictions and 16 similar sites without restrictions. Likewise, operational data were collected at 7 sites with restrictions and 6 similar sites without restrictions. The results of the analysis showed that the restrictions on two-lane sites appeared to be having a positive impact on operations and safety. At these sites, crashes were reduced by 23 percent, and speeds were estimated to have increased by 5.5 mph. At the three-lane sites, no statistically significant increase in speed was observed. A breakpoint in crash performance appeared to occur at approximately 10,000 vehicles per day per lane. Roads below this threshold experienced significantly fewer crashes than anticipated, whereas roads above this level had significantly more crashes than expected.
Download or read book A simulation analysis of traffic flow elements for restricted truck lanes on interstate highways in Virginia written by and published by . This book was released on 1999 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impacts and Effectiveness of Truck Lane Restrictions written by Sompong Sirisoponsilp and published by . This book was released on 1988 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 108 1 Hearing Truck Safety and Freight Mobility 108 15 March 24 2003 written by and published by . This book was released on 2004 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Operational Effects Safety Hazards Involved in Transporting 14 foot Wide Loads in Virginia written by Martin R. Parker and published by . This book was released on 1976 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the early 1950's, highways have been designed in Virginia to carry 8-foot wide vehicles on 12-foot lanes. Extralegal width vehicles impose detrimental operational effects and safety hazards on other highway users. To minimize the hazards, the Highway and Transportation Commission places restrictions on the movement of all extralegal size vehicles through permit regulations. Currently in Virginia, frequent numbers of loads up to and including those 12 feet in width are allowed to be operated on the highway on a routine permit basis. Loads above 12 feet wide have been allowed infrequently, and only when alternative measures have been exhausted. Recently the Virginia Housing Study Commission endorsed a proposal to transport frequent numbers of 14-foot wide housing units on the state's highways. A 14-foot wide load exceeds the width of a standard 12-foot traffic lane and creates more hazards for the motorist than do 12-foot wide loads Based on studies of 14-foot wide loads conducted in California and Florida and by the Midwest Research Institute, and data obtained from the Virginia State Police and highway personnel, the significant findings of this study are: 1. Regardless of initial requests to have 14-foot wide loads traverse only the highest type roads, they must eventually traverse all types to reach their ultimate destinations. 2. An 18-foot traffic lane is needed for the safe movement of a 14-foot wide load. Thus, for standard 12-foot traffic lanes, encroachment by the 14-foot load onto the shoulder and the adjacent traffic lane is necessary. 3. Only 5% of Virginia's highway system mileage consists of 12-foot traffic lanes. 4. A 14-foot wide load could physically use approximately 45% of Virginia's highway mileage, provided traffic was restricted to a one-way operation. 5. Thirty percent of the highway mileage in Virginia consists of 7-foot traffic lanes that would physically restrict, if not preclude, the movement of a 14-foot wide load.
Download or read book Engineering and Technology Measures to Improve Large Truck Safety written by Michael D. Fontaine and published by . This book was released on 2003 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to a request by Frank S. Wolf and Jo Ann Davis of the U.S. House of Representatives, Governor Mark Warner formed a Special Task Force on Truck Safety in the fall of 2002. The objective of the task force was to examine ways to reduce the number of crashes involving large trucks on Virginia's roads. One of the goals of this task force was to identify engineering and technology measures that have the potential to improve large truck safety. The task force charged the Virginia Transportation Research Council with identifying engineering and technology measures that offer the potential to improve large truck safety. A literature review of these areas was conducted, and a survey of personnel in the Virginia Department of Transportation (VDOT) was also carried out (1) to determine what measures have been implemented in Virginia, and (2) to solicit ideas for additional improvements. Traffic control improvements, geometric design changes, and intelligent transportation systems that improve truck safety are summarized in this report, and survey respondents. Recommendations for potential initiatives in engineering, enforcement, and education are also presented. The research showed that VDOT has already taken many actions to improve large truck safety issues and that further action could be taken in several areas: 1. VDOT's Mobility Management Division (MMD) should consider encouraging the use of dynamic truck speed advisory systems on freeway ramps where there are large numbers of rollover crashes. 2. VDOT's Location & Design Division should examine whether current design standards are adequate for the current truck fleet. 3. The MMD should consider developing guidelines for providing advance warning of the start of the red phase at intersections with limited sight distance. 4. The MMD should reexamine whether the truck lane restrictions are producing safety improvements. In addition to these measures, VDOT should continue to pursue the initiatives that are already underway, for example, the rumble strip program and measures to improve traveler information.
Download or read book Identifying the Impact of Truck lane Restriction Strategies on Traffic Flow and Safety Using Simulation written by Qun Liu and published by . This book was released on 2007 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continuous growth of freight transportation over recent years has resulted in an increasing proportion of commercial vehicles on our nations' highways which has led to higher truck volumes and more severe truck-related crashes every year. Safety proponents have therefore been advocating for more restrictions to be placed on these commercial vehicles in order to reduce the interaction of these larger vehicles and passenger cars. A popular strategy is the use of different lane restrictions for trucks. However, the effectiveness of these restrictions for trucks differs from case to case due to unique factors of each site, including the type of restriction used, traffic conditions and the geometric characteristics at the site. This has motivated the author to conduct this study to evaluate the impact of these restrictions on traffic operations and safety on freeways with different traffic and geometric characteristics. For the safety evaluation, this research measures the impact of different truck lane restriction strategies (TLRS) using conflict as the measurement of effectiveness (MOE). Conflict has been proven to be highly related to traffic crushes on freeways (FHWA, 1990; Sayed and Zein, 1999; Kaub, 2000). The high frequency of conflicts has also made it possible to collect adequate data for statistical analysis. The MOEs used to evaluate the impact of different lane restrictions on operational performance were lane changes, average speed, speed distribution, and volume distribution. Due to the lack of existing highway locations with different lane restrictions considered in this study, the conflict data were collected using a traffic simulation tool - PARAMICS V3.0 (Quadstone Ltd., 2000), which can simulate the emergent interaction between vehicles but not random crashes on the road network. The effectiveness of different lane restrictions in terms of the above MOEs were evaluated for 14,400 different simulation scenarios by varying lane restriction strategies, traffic conditions (volume, truck percentage) and geometric characteristics (gradient, speed limit, interchange density). The simulation results showed that all the geometric and traffic characteristics had a significant impact on freeway safety and operation. In addition, truck percentage and volume were identified as key factors that had a significant impact on the selection of the optimal truck lane restriction strategy. The ANOVA analyses indicated that the degree of effect of truck lane restriction strategies on safety intensify with the increase in truck percentage and traffic volume. Optimal alternatives of truck lane restriction strategies under different truck percentages and volumes were identified with the objective of reducing traffic conflicts and enhancing LOS (level of service). Guidelines were then developed for the application of truck lane restrictions under alternative traffic and geometric conditions.
Download or read book Truck Safety and Freight Mobility written by United States. Congress. House. Committee on Transportation and Infrastructure. Subcommittee on Highways, Transit, and Pipelines and published by . This book was released on 2003 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Highway heavy Vehicle Interaction written by Douglas W. Harwood and published by Transportation Research Board. This book was released on 2003 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's Commercial Truck and Bus Safety Synthesis Program (CTBSSP) Synthesis 3: Highway/Heavy Vehicle Interaction reports on the safety interactions of commercial trucks and buses with highway features and on highway improvements that can be made to improve the safety of heavy vehicle operations.
Download or read book Quantify the Effects of Raising the Minimum Speed on Rural Freeways and the Effects of Restricting the Truck Lanes Only in the Daytime written by Renatus Mussa and published by . This book was released on 2004 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Operational Evaluation of Truck Restrictions on Six lane Rural Interstates in Texas written by Michael C. Zavoina and published by . This book was released on 1990 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the increased expansion of rural Interstates to six lanes, questions have arisen as to the proper operational strategy of those facilities. One approach is to restrict trucks and other large vehicles from one or more of the lanes. The effects of such a restriction, however, have not been extensively studied. This study analyzes the operational effects of three left-lane truck restrictions on six-lane rural Interstates in Texas. Although the directional distribution of trucks changed significantly, no effects were found on the directional distribution of cars, the time gaps between vehicles, or the speeds of either cars or trucks that could be attributed to the truck restriction.
Download or read book Truck Operations and Regulations on Urban Freeways written by William R. McCasland and published by . This book was released on 1984 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Considering lane restrictions, time-of-day restrictions, speed restrictions, route restrictions, driver training certification and enforcement with application to Texas.
Download or read book Analysis and Evaluation of Truck Traffic Restrictions and Separation Methods on Interstate Highways Final Report written by Heather Lyn Wishart and published by . This book was released on 1996 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:
