Author: Nicholas J. GarberPublisher:
ISBN:
Category : Roads
Languages : en
Pages : 30
Book Description
The Effect of Trailer Width and Length on Large-truck Accidents
Author: Nicholas J. GarberPublisher:
ISBN:
Category : Roads
Languages : en
Pages : 30
Book Description
The Effect of Truck Size and Weight on Accident Experience and Traffic Operations. Volume III: Accident Experience of Large Trucks. Final Report
Author: G. R. ValletteA REVIEW OF The Effect of Truck Size and Weight on Accident Experience and Traffic Operations, Volume III: Accident Experience of Large Trucks
Author: Robert E. ScottThe Effect of Truck Size and Weight on Accident Experience and Traffic Operations. Volume 1: Executive Summary. Final Report
Author: G. R. ValletteRegulation of Weights, Lengths, and Widths of Commercial Motor Vehicles
Author: Transportation Research BoardPublisher: National Academies Press
ISBN: 030907701X
Category : Transportation
Languages : en
Pages : 283
Book Description
TRB Special Report 267 - Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles recommends the creation of an independent public organization to evaluate the effects of truck traffic, pilot studies of new truck designs, and a change in federal law authorizing states to issue permits for operation of larger trucks on the Interstates. In 1991, Congress placed a freeze on maximum truck weights and dimensions. Some safety groups were protesting against the safety implications of increased truck size and weight, and the railroads were objecting to the introduction of vehicles they deemed to have an unfair advantage. Railroads, unlike trucking firms, must pay for the capital costs of their infrastructure. The railroads contend that large trucks do not pay sufficient taxes to compensate for the highway damage they cause and the environmental costs they generate. Although Congress apparently hoped it had placed a cap on maximum truck dimensions in 1991, such has not proven to be the case. Carriers operating under specific conditions have been able to seek and obtain special exceptions from the federal freeze by appealing directly to Congress (without any formal review of the possible consequences), thereby encouraging additional firms to seek similar exceptions. In the Transportation Equity Act for the 21st Century, Congress requested a TRB study to review federal policies on commercial vehicle dimensions. The committee that undertook the study that resulted in Special Report 267 found that regulatory analyses of the benefits and costs of changes in truck dimensions are hampered by a lack of information. Regulatory decisions on such matters will always entail a degree of risk and uncertainty, but the degree of uncertainty surrounding truck issues is uunusually high and unnecessary. The committee concluded that the uncertainty could be alleviated if procedures were established for carrying out a program oof basic and applied research, and if evaluation and monitoring were permanent components of the administration of trucking regulations. The committee recommended immediate changes in federal regulations that would allow for a federally supervised permit program. The program would permit the operation of vehicles heavier than would normally be allowed, provided that the changes applied only to vehicles with a maximum weight of 90,000 pounds, double trailer configurations with each trailer up to 33 feet, and an overall weight limit governed by the federal bridge formula. Moreover, enforcement of trucks operating under such a program should be strengthened, and the permits should require that users pay the costs they occasion. States should be free to choose whether to participate in the permit program. Those that elected to do so would be required to have in place a program of bridge management, safety monitoring, enforcement, and cost recovery, overseen by the federal government. The fundamental problem involved in evaluating proposals for changes in truck dimensions is that their effects can often only be estimated or modeled. The data available for estimating safety consequences in particular are inadequate and probably always will be. Thus, the committee that conducted this study concluded that the resulting analyses usually involve a high degree of uncertainty. What is needed is some way to evaluate potential changes through limited and carefully controlled trials, much as proposed new drugs are tested before being allowed in widespread use. The committee recommended that a new independent entity be created to work with private industry in evaluating new concepts and recommending changes to regulatory agencies. Limited pilot tests would be required, which would need to be carefully designed to avoid undue risks and ensure proper evaluation. Special vehicles could be allowed to operate under carefully controlled circumstances, just as oversize and overweight vehicles are allowed to operate under special permits in many states. Changes in federal laws and regulations would be required to allow states to issue such permits on an expanded network of highways, under the condition that a rigorous program of monitoring and evaluation be instituted.Special Report 269 Summary
Operational Impacts of Wider Trucks on Narrow Roadways
Author: David L. HarkeyPublisher:
ISBN:
Category : Pavements
Languages : en
Pages : 140
Book Description
This study was conducted to determine the differences in performance between 102-in. (259-cm) wide and 96-in. (244-cm) wide trucks and the impact that these trucks have on other traffic. Trucks which were studied primarily included random trucks in the traffic stream, although a limited amount of control truck data were also collected to account for driver differences. Truck data were collected on rural two-lane and multilane roads which included curve and tangent sections and a variety of roadway widths and traffic conditions. The data collection effort resulted in approximately 100 hours of videotape and 9,000 slides from which various measures of effectiveness (MOEs) were extracted. A number of MOEs were used to test for the operational effects of differential truck widths, lengths, and configurations. Such measures included: (1) lateral placement of the truck and the opposing or passing vehicle, (2) lane encroachments by the truck or opposing vehicle, and (3) edgeline encroachments by the truck or opposing vehicle.
The Effect of Truck Size and Weight on Accident Experience and Traffic Operations. Volume IV: Truck Exposure Classification by Size and Weight. Final Report
Author: G. R. ValletteThe Effect of truck size and weight on accident experience and traffic operations
Author: Publisher:
ISBN:
Category : Traffic accidents
Languages : en
Pages :
Book Description
This report describes two major studies that were conducted to determine the effect of truck size and weight on accident experience and traffic operations. The first study involved a field evaluation of the effect of truck size and weight on traffic operations. The second study addressed the effect of truck size and weight on accident experience. The field study examined traffic operational effects associated with truck size and weight. Selected highway geometric conditions were: upgrades (short, long; slight, steep), downgrades (long, steep), curves (freeway, non-freeway), grade/curve combinations, merge areas, ramps, and urban intersections. Matched weight and operational data were gathered on nearly 6,000 trucks ranging in gross weight from approximately 20,000 to 160,000 pounds. Extensive traffic operations measures obtained via electronic roadway sensors included: flow (e.g., speed, acceleration), perturbations (e.g., speed variance, deviation from traffic speed), accident potential (e.g., closure rate, projected collision time), delay (e.g., speed delays by following vehicles), and passing behavior (e.g., relative passing speed). The objective of the accident study was to determine the effect the size and weight of large trucks has on accidents and traffic operations. The effect on accidents was determined by comparing the accident rates for a variet of truck types defined in terms of configuration, size, and weight. The accident rate is obtained by dividing the number of accidents of a specific truck type, size, and weight by the exposure mileage (opportunity to have an accident) for that same truck type, size, and weight. Data were collected for all large truck accidents occurring on 78 roadway segments in six states. In total, 2,112 accident involvements were investigated in-depth over a 1-1/2-year period in 1976-1977.
A Synthesis of Safety Implications of Oversize/overweight Commercial Vehicles
Author: Publisher: AASHTO
ISBN: 1560514663
Category : Commercial vehicles
Languages : en
Pages : 113
Book Description
The objective of this report is to identify known relationships between commercial vehicle safety and crash causation factors and to prepare a synthesis of safety implications of oversize/overweight (OS/OW) commercial vehicles. This information can be used to support commercial vehicle enforcement and permitting practices and justify expenditures and investments on size and weight enforcement to enhance safety. In producing this report, insight was gained into the impacts of truck size and weight (TSW) regulations through three case studies. The state of practice in estimating large truck crash rates is complicated because of the many configurations and the wide range of possible weights for any particular configuration. This report highlights four primary findings regarding the contributions of OS/OW to commercial vehicle crashes found by its researchers.
Twin Trailer Trucks
Author: National Research Council (U.S.). Transportation Research BoardPublisher: National Academies Press
ISBN:
Category : Business & Economics
Languages : en
Pages : 412
Book Description
TRB Special Report 211: Twin Trailer Trucks examines the potential safety effects of the new federal truck size rules (the Surface Transportation Act of 1982 requires states to permit twin 28-ft trailers on Interstate highways and on principal roads). The study also addressed other effects of the new rules on highway transportation including the trucking industry use of twins, safety consequences of twins, pavement wear and other highway features affected by twins, and safety and pavement wear affected by 48-ft long semitrailers and 102- in. wide trucks. The use of twin trailer trucks will be concentrated in the general freight common carriers sector and will result in a 9% reduction in combination-truck miles in the portion of their hauling that is switched from tractor-semitrailers to twins. It is not expected that either the scope of the current highway network or restrictions on access to that network will have an impact on travel by twins. The increased use of twins will have little overall effect on highway safety. However, twins will accelerate pavement wear and increase rehabilitation costs. The use of 102-in. wide trucks and 48- ft semitrailers (also permitted by the 1982 law) also increases pavement wear. Recommendations are presented that would help coordinate the efforts of various data producers and users of programs that collect nationwide information on truck travel, safety, and highway impact, and thus enhance their ability to provide data addressing policy questions. Recommendations are also made for improving the safety of the vehicles. The various chapters of the book cover the study method and report organization; the historical and regulatory background; use characteristics and cost impacts; safety impacts; highway condition, operation and design impacts; long-term monitoring; and conclusions drawn from the study.