The Potential Benefits of Exclusive Lanes for Trucks and Cars on Interstate Highways in Virginia PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download The Potential Benefits of Exclusive Lanes for Trucks and Cars on Interstate Highways in Virginia PDF full book. Access full book title The Potential Benefits of Exclusive Lanes for Trucks and Cars on Interstate Highways in Virginia by Joseph Edgar Vidunas. Download full books in PDF and EPUB format.
Author: Joseph Edgar Vidunas
Publisher:
ISBN:
Category :
Languages : en
Pages : 166
Get Book Here
Book Description
Author: Joseph Edgar Vidunas
Publisher:
ISBN:
Category :
Languages : en
Pages : 166
Get Book Here
Book Description
Author: Lester A. Hoel
Publisher:
ISBN:
Category : Express highways
Languages : en
Pages : 106
Get Book Here
Book Description
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.
Author: Michael D. Fontaine
Publisher:
ISBN:
Category : Express highways
Languages : en
Pages : 39
Get Book Here
Book Description
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.
Author: Lester A. Hoel
Publisher:
ISBN:
Category : Express highways
Languages : en
Pages : 38
Get Book Here
Book Description
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.
Author: United States. Congress. House. Committee on Public Works
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 36
Get Book Here
Book Description
Author: United States. Federal Highway Administration
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 44
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Air travel
Languages : en
Pages : 616
Get Book Here
Book Description
Author: Joseph E. Vidunas
Publisher:
ISBN:
Category : Express highways
Languages : en
Pages : 15
Get Book Here
Book Description
Author: Michael D. Fontaine
Publisher:
ISBN:
Category : Express highways
Languages : en
Pages : 41
Get Book Here
Book Description
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.
Author: Jack D. Jernigan
Publisher:
ISBN:
Category : Interstate Highway System
Languages : en
Pages : 158
Get Book Here
Book Description
In April of 1987, Congress passed the Surface Transportation and Uniform Relocation Assistance Act of 1987, which allows the states to raise, without penalty, the speed limit on interstate highways outside of urbanized areas with a population of 50,000 or more. This study estimated that an increase in the rural interstate speed limit in Virginia would have both positive and negative outcomes.-The average speed traveled on the rural interstate highway system has already increased by 3.6 mph in Virginia; this is comparable to that experienced in states that have raised the speed limit. However, if the speed limit on the rural interstate highway system is raised from 55 mph to 65 mph, it is estimated that in the short run the average speed traveled on the rural interstate will increase by an additional 3 mph, from 60 mph to 63 mph. Increased speeds would be expected to result in increased stopping distances and an annual increase of between 6 and 18 fatalities and between 171 and 405 injuries. Further, injuries would likely be more severe as a result of the higher speeds traveled. If the average speed continues to increase in the long run, or if higher speeds spill over onto the urban interstate highway system or rural collector roads, then additional injuries and fatalities would be expected on those systems as well. On the other hand, the primary quantifiable benefit of the higher limit would be a savings of 1.3 million hours in business and commercial travel time. This study has also found that almost 60% of the Virginians surveyed would prefer a 65 mph speed limit to a 55 mph limit on the rural interstate highway system. Finally, because of the current speeds, the geometric design, and the accident history of the rural interstates in general, it would be possible to raise the speed limit without violating traffic engineering tenets for setting speed limits. However, if the speed limit is raised, establishing a truck speed limit differential below the limit established for passenger cars would promote increased speed variance between cars and trucks, thereby creating a more dangerous environment than if the speed limit were raised to the same level for both cars and trucks.
