Study of Long Combination Vehicles on Two-Lane Highways

1998 ◽  
Vol 1613 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Raymond A. Barton ◽  
John Morrall
Keyword(s):  
High Speed ◽  
Rocky Mountain ◽  
Highway Safety ◽  
Level Of Service ◽  
Western Canada ◽  
Maximum Volume ◽  
Vehicle Type ◽  
Heavy Trucks ◽  
Traffic Volumes ◽  
Council Of Ministers

In 1988, the Council of Ministers of Transportation and Highway Safety in Canada endorsed a memorandum of understanding designed to improve uniformity between provinces and territories. The regulations covering weights and dimensions for tractor-semitrailers and double combination trucks specified a maximum length of 23 m. However, in western Canada, which includes the provinces of British Columbia, Alberta, Saskatchewan, and Manitoba, a maximum vehicle length of 25 m was adopted. Vehicles longer than 25 m are generally referred to as long combination vehicles (LCVs) and include the following vehicles: triple trailer combinations, 35 m in length; Rocky Mountain doubles, 30 m in length; log haul trucks, which can be up to 30.5 m in length; and turnpike doubles, 38 m in length. A study was conducted to develop recommendations relating to the use of LCVs on two-lane highways in Alberta. The basic approach was to examine the incremental impact of LCV-type vehicles on two-lane highway operations compared with a baseline vehicle type, namely, 25-m standard double heavy trucks. Although the study of LCVs examined a range of issues that included low- and high-speed offtracking, and aerodynamic buffeting, only the findings related to traffic volume criteria are presented. The main recommendation with respect to passing opportunities and level of service was the development of maximum traffic volumes for two-lane highways with and without passing lanes and with a given percentage of passing zones. The main criteria are to ensure that a net passing opportunity of at least 30 percent is provided to drivers impeded by LCVs. This is roughly comparable to providing to Level of Service C. For example, the maximum volume below which Rocky Mountain doubles may operate on a two-lane highway is 425 veh/h for a section with 100 percent passing zones. If 2-km passing lanes are provided every 10 km, Rocky Mountain doubles could operate at traffic volumes up to 734 veh/h and still ensure a net passing opportunity of 30 percent.

scholarly journals Vehicle and Pedestrian Level of Service in Street Designs with Elements of Shared Space

2020 ◽  
Vol 2674 (9) ◽  
pp. 1084-1096
Author(s):  
Ioannis Kaparias ◽  
Rui Wang
Keyword(s):  
Video Data ◽  
Road User ◽  
Level Of Service ◽  
Highway Capacity ◽  
Vehicle Traffic ◽  
Highway Capacity Manual ◽  
Shared Space ◽  
Before And After ◽  
Traffic Volumes

Inspired by developments in urban planning, the concept of “shared space” has recently emerged as a way of creating a better public realm. This is achieved through a range of streetscape treatments aimed at asserting the function of streets as places by facilitating pedestrian movement and lowering vehicle traffic volumes and speeds. The characteristics of streets with elements of shared space point to the conjecture that traffic conditions and road user perceptions may be different to those on streets designed according to more conventional principles, and this is likely to have an impact on the quality of service. The aim of this paper is, therefore, to perform an analysis in relation to level of service (LOS) and to investigate how this may change as a result of the implementation of street layouts with elements of shared space. Using video data from the Exhibition Road site in London during periods before and after its conversion from a conventional dual carriageway to a layout featuring several elements of shared space, changes in relation to LOS for both vehicle traffic and pedestrians are investigated, by applying the corresponding methods from the 2010 Highway Capacity Manual. The results suggest that streets with elements of shared space provide a much improved pedestrian experience, as expressed by higher LOS ratings, but without compromising the quality of vehicle traffic flow, which, in fact, also sees slight improvements.

Evaluation of weigh-in-motion in Manitoba

1999 ◽  
Vol 26 (5) ◽  
pp. 655-666 ◽  
Author(s):  
Xun Zhi ◽  
Ahmed Shalaby ◽  
Dan Middleton ◽  
Alan Clayton
Keyword(s):  
Primary Objective ◽  
Vehicle Classification ◽  
Design Management ◽  
Western Canada ◽  
Data Sets ◽  
Survey Period ◽  
Weigh In Motion ◽  
Large Numbers ◽  
Traffic Volumes ◽  
American Society

The primary objective of a weigh-in-motion (WIM) system is to provide highway designers and agencies with information on the loads and traffic volumes using a particular highway, thereby facilitating improved pavement design, management, and weight enforcement. In this paper, the historic performance of WIM systems in Manitoba is evaluated. The results indicate that large numbers of unreasonable data are produced from the WIM systems, calibration procedures are not standardized, and there is drift in calibration. The performance of the Brokenhead WIM system was evaluated through a detailed survey conducted at the Brokenhead WIM site and the Westhawk Permanent Truck Weigh Station in August 1997. The Brokenhead site is on the Trans-Canada highway east of Winnipeg. It is the only WIM system in the country that measures truck characteristics and movements between eastern and western Canada. The survey produced a large database permitting the comparison of truck dimension measurements, truck weights, and vehicle classification between those produced by the WIM system and those observed manually. The results indicate that WIM axle-spacing data sets were outside the tolerance for 95% conformity specified by the American Society for Testing and Materials (ASTM). The system classified 5 to 9 axle combination trucks more accurately than some 2- and 3-axle vehicles. The WIM system underestimated about 90% of truck weights in the survey period. The degree of underestimation exceeded 50% of the corresponding static weights. This finding highlights the importance of quality control and corrections on WIM data prior to their use in research or engineering practice.Key words: weigh-in-motion, vehicle classification, calibration, axle spacing, axle load.

Coccidia of Rocky Mountain bighorn sheep in Western Canada

1971 ◽  
Vol 49 (11) ◽  
pp. 1461-1464 ◽  
Author(s):  
Leslie S. Uhazy ◽  
Jerome L. Mahrt ◽  
John C. Holmes
Keyword(s):  
British Columbia ◽  
National Park ◽  
Rocky Mountain ◽  
Bighorn Sheep ◽  
Western Canada ◽  
Fecal Samples

A survey of coccidia in the Rocky Mountain bighorn sheep (Ovis. c. canadensis) in Alberta and Kootenay National Park, British Columbia, was conducted from the winter of 1967 to the spring of 1969. Ninety percent of 510 fecal samples examined were positive for coccidia. The species recovered, in order of prevalence, were Eimeria ovina (syn., E. arloingi) (56%), E. parva (35%), E. crandallis (34%), E. ahsata (33%), E. ninakohlyakimovae (19%), E. faurei (6%), E. intricata (5%) and E. granulosa (1%). Coccidiosis was not encountered in the field; however, evidence which suggests the magnitude of pathogenic infections is presented.

scholarly journals The Importance of Assessing the Level of Service in Confined Infrastructures: Some Considerations of the Old Ottoman Pedestrian Bridge of Mostar

2019 ◽  
Vol 9 (8) ◽  
pp. 1630 ◽  
Author(s):  
Tiziana Campisi ◽  
Antonino Canale ◽  
Giovanni Tesoriere ◽  
Ivan Lovric ◽  
Boris Čutura
Keyword(s):  
Action Plan ◽  
Research Work ◽  
Level Of Service ◽  
Emergency Situations ◽  
Depth Analysis ◽  
Traffic Volumes ◽  
Bridge Crossing ◽  
Definition Of ◽  
Surrounding Areas ◽  
Pedestrian Simulation

Walking is classified as the oldest transport mode with the least impact on the environment. It is frequently one of the intermediate transport modes. Generally, while designing exclusive walking transit areas or structures with high human traffic volumes and considering different scenarios, it is advantageous to be able to foresee the congestion conditions and the relative problems. The study of pedestrian trajectories, which are strictly related to the characteristics of the walkers, is necessary and preliminary for the purposes of an in-depth analysis linked to the habits of populations and cultures. Often areas crowded by tourists run, of limited size such as bridges, must be considered in advance for emergencies. This article focuses on an old footbridge of Mostar located in a confined area with an increasing tourist flow. The peculiarity of the bridge lies in the double-flight geometry with elements that generate discontinuity in the trajectory as well as the steps. This analysis was carried out obtaining the traffic data from video cameras and analyzing different scenarios on holidays and weekdays. Also, the possible presence of obstacles on the bridge was taken into account, such as some areas not walkable for temporary work or the presence of obstacles. These scenarios have been calibrated and simulated through the definition of O/D matrices, arcs and nodes (or areas) through the pedestrian simulation tool Viswalk. This comparison is useful for understanding the variation of LOS (Level of Service) during the daily or emergency situations and the results can provide help to local authorities to plan and design an appropriate action plan. Therefore, this research work aims to compare scenarios under critical flow conditions in the order to define preventively possible actions that can guarantee an optimal LOS value during the bridge crossing and the surrounding areas.

scholarly journals A Comparative Study on Drivers’ Stop/Go Behavior at Signalized Intersections Based on Decision Tree Classification Model

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Sheng Dong ◽  
Jibiao Zhou
Keyword(s):  
Decision Making ◽  
Decision Tree ◽  
High Speed ◽  
Signalized Intersections ◽  
Speed Limit ◽  
Vehicle Type ◽  
Decision Tree Classification ◽  
Signal Change ◽  
Signal Period ◽  
Instantaneous Speed

The stop/go decisions at signalized intersections are closely related to driving speed during signal change intervals. The speed during stop/go decision-making has a significant influence on the dilemma area, resulting in changes of stop/go decisions and high complexity of the decision-making process. Considering that traffic delays and vehicle exhaust pollution are mainly caused by queuing at intersections, the stop-line passing speed during the signal change interval will affect both vehicle operation safety and the atmospheric environment. This paper presents a comparative study on drivers’ stop/go behaviors when facing a transition signal period consisting of 3 s green flashing light (FG) and 3 s yellow light (Y) at rural high-speed intersections and urban intersections. For this study, 1,459 high-quality vehicle trajectories of five intersections in Shanghai during the transition signal period were collected. Of these five intersections, three are high-speed intersections with a speed limit of 80 km/h, and the other two are urban intersections with a speed limit of 50 km/h. Trajectory data of these vehicle samples were statistically analyzed to investigate the general characteristics of potential influencing factors, including the instantaneous speed and the distance to the intersection at the start of FG, the vehicle type, and so on. Decision Tree Classification (DTC) models are developed to reveal the relationship between the drivers’ stop/go decisions and these possible influencing factors. The results indicate that the instantaneous speed of FG onset, the distance to the intersection at the start of FG, and the vehicle type are the most important predictors for both types of intersections. Besides, a DTC model can offer a simple way of modeling drivers’ stopping decision behavior and produce good results for urban intersections.

Archaeocyathids and the Lower Cambrian Continental Shelf of the Canadian Cordillera

1975 ◽  
Vol 12 (12) ◽  
pp. 2014-2020 ◽  
Author(s):  
C. R. Stelck ◽  
A. S. Hedinger
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Lower Cambrian ◽  
Rocky Mountain ◽  
Canadian Cordillera ◽  
Western Canada ◽  
Early Cambrian ◽  
Structural Trend ◽  
East And West

The geographic occurrences of archaeocyathids are plotted for the Cordilleran region of western Canada. The archaeocyathids are found both east and west of, and within the Rocky Mountain Trench in British Columbia and are found east and west of the Tintina Trench in the southern Yukon. The overall pattern of the occurrences indicates that the shallow neritic portion of the continental shelf in Early Cambrian time traces a pattern widely diverse from that of the later, superimposed, Laramide structural trend. Portions of the continental shelf were already in existence west of the Rocky Mountain Trench by Early Cambrian time.

POPULATION DYNAMICS OF THE LODGEPOLE NEEDLE MINER, RECURVARIA STARKI FREEMAN, IN CANADIAN ROCKY MOUNTAIN PARKS

1959 ◽  
Vol 37 (6) ◽  
pp. 917-943 ◽  
Author(s):  
R. W. Stark
Keyword(s):  
Climatic Factors ◽  
Rocky Mountain ◽  
Warming Trend ◽  
Western Canada ◽  
Canadian Rocky Mountains ◽  
Control Factors ◽  
Egg Formation ◽  
Northern Latitudes ◽  
Winter Temperatures ◽  
Larval Establishment

The lodgepole needle miner, Recurvaria starki Freeman, has been studied intensively since 1948. Life tables, survival, and death-rate curves show clearly that there are five periods in the 2-year life cycle of the needle miner during which extensive mortality may occur: (1) between egg formation and oviposition; (2) between oviposition and larval establishment; (3) during the first larval hibernation; (4) during the second larval hibernation; (5) during the spring of moth emergence. Population success is also undoubtedly affected by conditions during the adult life.Population sampling has shown that the outbreak has declined since 1948. Defoliation and increment studies have shown that the period of greatest defoliation occurred from 1940 to 1944 and that the outbreak probably began in the late 1930's. The major cause of the decline was severe winter temperatures, probably during the coldest month. Parasitism was not an important factor in the outbreak decline, apparently because it was controlled in the same manner as the host, by winter temperatures. Other natural control factors are discussed as well as the possible effects of climatic factors on oviposition and fecundity.A detailed survey of weather records since 1920 and yearly averages since 1885 suggest that release of the needle miner population was due to a warming trend in the climate of western Canada. This trend began in the late 1930's, reached a peak in the mid-1940's, and has declined since that time. The warming trend in northern latitudes has been noted by other authors and is substantiated by weather records of this region. It is further postulated that the climate of the Canadian Rocky Mountains is generally too severe for an outbreak of the lodgepole needle miner to be prolonged.

Analyses of crustal structure from bandpass and directionally filtered potential-field data: an example from western Canada

2001 ◽  
Vol 38 (6) ◽  
pp. 953-961 ◽  
Author(s):  
Hugh D Geiger ◽  
Frederick A Cook
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Rocky Mountain ◽  
Western Canada ◽  
Potential Field Data ◽  
Directional Filtering ◽  
Crustal Structures ◽  
Depth Extent ◽  
Lower Crustal ◽  
Dextral Strike Slip

Application of bandpass and directional filtering to potential-field data in northwestern Canada allows separation of anomalies due to northwest-oriented upper crustal sources that are associated with Cordilleran structures from anomalies due to northeast-oriented lower crustal sources that are primarily associated with Precambrian Shield rocks. In northeastern British Columbia, northeast-trending lower crustal structures of the Canadian Shield as represented in the gravity patterns appear to project west of the Tintina fault – Northern Rocky Mountain Trench at about 56°N. About 400–500 km farther north, the Tintina fault may penetrate into the lithospheric mantle. It is, thus, likely that the depth extent of the Tintina fault rises southward into the crust, as dextral strike-slip motion is transformed into contractional structures of the southern Cordillera.

Study on the Intake Valve Close Timing Misalignment Between the Maximum Volume Efficiency and the None Backflow on a Single Cylinder Diesel Engine

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Fushui Liu ◽  
Zhongjie Shi ◽  
Yang Hua ◽  
Ning Kang ◽  
Yikai Li ◽  
...  
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Three Dimensional ◽  
Intake Valve ◽  
Maximum Volume ◽  
Single Cylinder ◽  
Gradual Process ◽  
The Mean ◽  
The Relationship ◽  
Volume Efficiency

Since the intake valve close timing (IVC) directly determines the amount of displacement backflow and the amount of fresh charge trapped in the cylinder, optimizing the IVC is important to improve the performance of the diesel engine. In this paper, the relationship between the IVC and the displacement backflow of the cylinder at the high-speed condition was studied by establishing a one-dimensional (1D) gas dynamic model of a single-cylinder diesel engine. The results show that the forward airflow mass of intake and the backflow increase as the IVC retards, and the airflow mass trapped in cylinder increases at first and then decreases. It is interesting to find that the backflow does not equal zero when the air mass trapped in cylinder is the largest, which is different from the traditional optimizing strategy on the IVC. That is to say, there exists a misalignment between the maximum-volume-efficiency IVC and the none-backflow IVC. To further verify this interesting misalignment, the airflow characteristics at the optimized IVC condition are studied by establishing a three-dimensional (3D) simulation. It is found that the appearance of backflow is a gradual process, and there exists an overall backflow when the engine volume efficiency reaches its maximum value. In addition, the misalignment is reduced as the mean valve-closing velocity increases. The misalignment equals to 0 only if the mean valve-closing velocity approaches infinity.

Comfortable Driving Speed Evaluated

1983 ◽  
Vol 27 (4) ◽  
pp. 330-333
Author(s):  
Dennis J. Seal
Keyword(s):  
Vehicle Design ◽  
Maximum Speed ◽  
Speed Limit ◽  
Driving Experience ◽  
Vehicle Type ◽  
Sound Levels ◽  
Driving Speed ◽  
Federal Highway ◽  
Traffic Volumes ◽  
Age Category

Since its enactment in 1974, the National Maximum Speed Limit (NmSL) of 55 miles per hour has remained a controversial law. Despite the enforcement efforts, recent studies have found that approximately 20 percent of all American motorists exceed the 55 m.p.h. limit. However, legislation still requires individual states to enforce the law or else forfeit millions of dollars in federal highway aid. This study examined three questions: (a) is there a preferred speed that drivers find comfortable during travel, (b) how does it compare with the national speed limit, and (c) what is its relationship to vehicle design and driver characteristics? Taken into account were factors that made the study representative of national highway driving. For example, each of the 100 participants was selected on the basis of demographics one finds in the driving population (i.e., age category, sex, driving experience and vehicle type). Furthermore, each participant used his own vehicle to drive a highway route of 60 miles, which included typical highway settings (two-lane and four-lane, divided and un-divided) with average traffic volumes. So that the speed was truly a matter of preference, the instrument panels were covered and the only true indication of velocity was the highway environment, other vehicles, or the vestibular sense. An accelerometer was used to record both the vibration and sound levels of the sampled vehicles. The results showed that the subjects in the study preferred a comfortable driving speed which exceeded the national maximum speed limit. More specifically, in regard to the 55 m.p.h. speed limit, the study revealed: (a) only 37% of the drivers preferred to drive 55 m.p.h. or less, (b) 34% of the drivers preferred to exceed 55 m.p.h. by 5 m.p.h., and (c) 29% of the sample established a comfortable speed of 60 m.p.h. or greater. The results of this study are indicative of the fact that highway drivers prefer to drive at a speed in excess of 55 m.p.h. For this reason it is recommended that consideration be given to raising the national speed limit to 60 m.p.h., thereby bringing it into line with an average speed that the majority of drivers prefer. This law would help to lower the variance of highway speeds and thus reduce the number of accidents and fatalities on our national highways. This investigation also demonstrated significant differences in preferred driving speeds between age categories. The younger drivers in this study (i.e., 16–29) preferred speeds well above the national speed limit of 55 m.p.h. Such results have important implications for the State Licensing Bureau.

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