Study of Speed-Flow Relationships on Individual Freeway Lanes

1997 ◽  
Vol 1591 (1) ◽  
pp. 7-13 ◽  
Author(s):  
V. F. Hurdle ◽  
Mark I. Merlo ◽  
Doug Robertson
Keyword(s):  
Practical Interest ◽  
Linear Functions ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Speed Flow ◽  
High Flows ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Very High

Many researchers have examined the form of the relationship between speed and flow on freeways. However, these researchers have concentrated on relationships for the freeway as a whole instead of on individual lanes. In this study, the relationship was examined for each of the three lanes at two locations on Highway 401 in metropolitan Toronto. It proved possible to accurately describe the mean speed in each lane with simple linear functions over the range of flows of most practical interest. Cubic functions provided comparable results over a wider range of flows, but it appears unlikely that the very high and very low flows are of sufficient interest to justify the added complexity. When an attempt was made to examine the relationship between speed and flow for the entire roadway, the linear functions were not adequate, but cubic functions performed reasonably well. However, the details of the full roadway curves are quite different from those of the curves described in the 1994 Highway Capacity Manual. In particular, the curves described in the manual are much steeper than the Highway 401 curves at high flows, implying a much more rapid loss of performance as flow approaches capacity than was observed. The full roadway curves are also surprisingly different from the curves for the individual lanes.

Predicting Lane-by-Lane Flows and Speeds for Freeway Segments

2020 ◽  
Vol 2674 (9) ◽  
pp. 1052-1068
Author(s):  
Fabio Sasahara ◽  
Luan Guilherme Staichak Carvalho ◽  
Tanay Datta Chowdhury ◽  
Zachary Jerome ◽  
Lily Elefteriadou ◽  
...  
Keyword(s):  
Field Data ◽  
Performance Estimation ◽  
Free Flow ◽  
Highway Capacity ◽  
Distribution Models ◽  
Highway Capacity Manual ◽  
Speed Flow ◽  
Flow Speeds ◽  
The Relationship

The Highway Capacity Manual is a major reference for evaluating the capacity and quality of service of road facilities. However, it holds the assumption that lanes perform equally, which can result in inaccuracies in performance estimation. The main purpose of this research is to develop a series of models for estimating flows and speeds by lane for various types of freeway segments, including basic, merge, and diverge types. These models consider the demand-to-capacity ratio, the presence of trucks, grade, and the presence of upstream and downstream ramps. To predict lane performance effectively, it is critical that capacity and free-flow speeds are also determined for individual lanes. Therefore, this study also investigates the relationship between segment average values and lane values for free-flow speeds and capacities, and proposes a method to estimate these parameters for each lane as a function of the segment average. Observed field data has shown that free-flow speeds and capacities have lowest values on the shoulder lanes and highest values on the median lanes. Speed and flow data were collected from 48 segments throughout the U.S.A., including basic, merge, and diverge segments, to develop flow and speed distribution models. A case example is provided to illustrate the application of the developed model and the predicted speed–flow relationship is compared with field data, with satisfactory results.

scholarly journals Capacity of Advance Right-Turn Motorized Vehicles at Signalized Intersections for Mixed Traffic Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Bing Li ◽  
Wei Cheng ◽  
Yiming Bie ◽  
Bin Sun
Keyword(s):  
Arrival Rate ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Traffic Conditions ◽  
Capacity Model ◽  
Conflict Zone ◽  
Traffic Conflict ◽  
Motorized Vehicles ◽  
The Relationship ◽  
Gap Acceptance Theory

Right-turn motorized vehicles turn right using channelized islands, which are used to improve the capacity of intersections. For ease of description, these kinds of right-turn motorized vehicles are called advance right-turn motorized vehicles (ARTMVs) in this paper. The authors analyzed four aspects of traffic conflict involving ARTMVs with other forms of traffic flow. A capacity model of ARTMVs is presented here using shockwave theory and gap acceptance theory. The proposed capacity model was validated by comparison to the results of the observations based on data collected at a single intersection with channelized islands in Kunming, the Highway Capacity Manual (HCM) model and the VISSIM simulation model. To facilitate engineering applications, the relationship describing the capacity of the ARTMVs with reference to the distance between the conflict zone and the stop line and the relationship describing the capacity of the ARTMVs with reference to the effective red time of the nonmotorized vehicles moving in the same direction were analyzed. The authors compared these results to the capacity of no advance right-turn motorized vehicles (NARTMVs). The results show that the capacity of the ARTMVs is more sensitive to the changes in the arrival rate of nonmotorized vehicles when the arrival rate of the nonmotorized vehicles is 500  (veh/h)~2000  (veh/h) than when the arrival rate is some other value. In addition, the capacity of NARTMVs is greater than the capacity of ARTMVs when the nonmotorized vehicles have a higher arrival rate.

Monitoring Training Volume Through Maximal Number of Repetitions or Velocity-Based Approach

2020 ◽  
pp. 1-8
Author(s):  
Miguel Sánchez-Moreno ◽  
Gonçalo Rendeiro-Pinho ◽  
Pedro V. Mil-Homens ◽  
Fernando Pareja-Blanco
Keyword(s):  
Coefficient Of Variation ◽  
Bench Press ◽  
Interindividual Variability ◽  
Load Condition ◽  
Velocity Relationship ◽  
The Mean ◽  
Monitoring Training ◽  
The Individual ◽  
The Relationship ◽  
Level Of Effort

Purpose: This study aimed (1) to analyze the interindividual variability in the maximal number of repetitions (MNR) performed against a given relative load (percentage of 1-repetition maximum [%1RM]) and (2) to examine the relationship between the velocity loss (VL) magnitude and the percentage of completed repetitions with regard to the MNR (%Rep), when the %1RM is based on individual load–velocity relationships. Methods: Following an assessment of 1RM strength and individual load–velocity relationships, 14 resistance-trained men completed 5 MNR tests against loads of 50%, 60%, 70%, 80%, and 90% 1RM in the Smith machine bench-press exercise. The relative loads were determined from the individual load–velocity relationship. Results: Individual relationships between load and velocity displayed coefficients of determination (R2) ranging from .986 to .998. The MNR showed an interindividual coefficient of variation ranging from 8.6% to 33.1%, increasing as the %1RM increased. The relationship between %Rep and the magnitude of VL showed a general R2 of .92 to .94 between 50% and 80% 1RM, which decreased to .80 for 90% 1RM. The mean individual R2 values were between .97 and .99 for all loading conditions. The %Rep when a given percentage of VL was reached showed interindividual coefficient of variation values ranging from 5% to 20%, decreasing as the %Rep increased in each load condition. Conclusions: Setting a number of repetitions had acceptable interindividual variability, with moderate relative loads being adjusted based on the individual load–velocity relationship. However, to provide a more homogeneous level of effort between athletes, the VL approach should be considered, mainly when using individual VL–%Rep relationships.

Lane-by-Lane Analysis Framework for Conducting Highway Capacity Analyses at Freeway Segments

2019 ◽  
Vol 2673 (8) ◽  
pp. 523-535
Author(s):  
Fabio Sasahara ◽  
Lily Elefteriadou ◽  
Shen Dong
Keyword(s):  
Flow Distribution ◽  
Time Of Day ◽  
Heavy Vehicles ◽  
Highway Capacity ◽  
Operational Conditions ◽  
Highway Capacity Manual ◽  
Loop Detectors ◽  
Speed Flow ◽  
Flow Speeds ◽  
The Usa

The Highway Capacity Manual (HCM) methodology for freeway systems yields average speed values for each segment and does not consider lane-by-lane flow and operational conditions. However, flows are not equally distributed between lanes. In congested conditions and particularly when spillback occurs, flows and traffic conditions vary widely. For example, the rightmost lane may be blocked while the leftmost lane is free-flowing. The purpose of this research is to develop a model for estimating lane-by-lane speeds and flows under various freeway designs and demands. Speed and flow data from loop detectors at several locations around the USA were collected, totaling 531,000 observations aggregated in 15-min intervals. The results show that lane flow distribution is highly dependent on the segment total flow, with different patterns for 4-, 6-, and 8-lane segments. The percentage of heavy vehicles, presence of nearby ramps, day of week, and time of day also affect the distribution of flow among freeway lanes. Theoretical lane-by-lane speed-flow curves were developed and the results were compared with field data. Results showed that lane-by-lane speeds can be estimated accurately, as long as inputs for capacity and free-flow speeds can be provided for each lane in the segment.

A Behavioral Process Approach to Information Acquisition in Nondurable Purchasing

1978 ◽  
Vol 15 (4) ◽  
pp. 532-544 ◽  
Author(s):  
Jacob Jacoby ◽  
Robert W. Chestnut ◽  
William A. Fisher
Keyword(s):  
Information Search ◽  
Information Acquisition ◽  
Consumer Information ◽  
Behavioral Process ◽  
The Mean ◽  
The Individual ◽  
Attitudinal Brand Loyalty ◽  
Available Information ◽  
Relationship Of ◽  
The Relationship

A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of available information actually acquired was 2%, and (2) information search was concentrated on six of the 35 available information dimensions; increased information acquisition was related (3) positively to the product's importance for the individual, (4) positively to being an optimizer rather than a satisficer, (5) positively to high amounts of past purchasing experience with the product, and (6) negatively to attitudinal brand loyalty.

scholarly journals Caregiver distress associated with behavioral and psychological symptoms in mild Alzheimer's disease

2010 ◽  
Vol 4 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Ari Pedro Balieiro Jr. ◽  
Emmanuelle Silva Tavares Sobreira ◽  
Marina Ceres Silva Pena ◽  
José Humberto Silva-Filho ◽  
Francisco de Assis Carvalho do Vale
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Psychological Symptoms ◽  
Time Behavior ◽  
Caregiver Distress ◽  
Night Time ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Behavioral And Psychological Symptoms

Abstract The aim of this study was to analyze the relationship between Caregiver Distress and Behavioral and Psychological Symptoms in Dementias (BPSD) in mild Alzheimer's disease. Methods: Fifty patients and caregivers were interviewed using the Neuropsychiatric Inventory (NPI). Results: 96.0% of the patients had at least one BPSD. The mean NPI total score was 19.6 (SD=18.05; range=0-78) whereas the mean Caregiver Distress Index (CDI) total score was 11.5 (SD=10.41; range=0-40). For the individual symptoms, the weighted mean CDI was 2.8 (SD=1.58). All symptom CDI means were higher than 2.0 except for euphoria/elation (m=1.8; SD=1.49). There were correlations between CDI and derived measures (Frequency, Severity, FxS, and Amplitude) for all symptoms, except Disinhibition and Night-time behavior. Correlations ranged between 0.443 and 0.894, with significance at p<0.05. Conclusions: All the derived measures, including amplitude, were useful in at least some cases. The data suggests that CDI cannot be inferred from symptom presence or profile. Symptoms should be systematically investigated.

Relationship between Rated Degree of Familiarity with Individual Sentences and the Extent of Recall of Connected Discourse

1966 ◽  
Vol 19 (3_suppl) ◽  
pp. 1195-1202 ◽  
Author(s):  
John A. Mills ◽  
Alan Nicolas-Fanourakis
Keyword(s):  
Rating Scale ◽  
Interference Theory ◽  
Connected Discourse ◽  
Wide Range ◽  
The Mean ◽  
The Individual ◽  
The Relationship

An assessment was made of the strength and direction of the relationship between rated degree of familiarity for connected discourse and the extent of recall of such material. The experimental material consisted of two short passages of prose (a narrative and an argument) and of a rating scale containing all the sentences from these passages inserted randomly among other individual sentences selected from a wide range of sources. 20 Ss provided both recall scores for the passages (which were presented whole) and familiarity ratings for the sentences in the rating scale. When recall scores for the individual sentences were correlated with the mean ratings, a positive and significant value was found. The bearing of this finding on (he expectations of interference theory is discussed.

Improved Speed-Flow Relationships for Planning Applications

1997 ◽  
Vol 1572 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Alexander Skabardonis ◽  
Richard Dowling
Keyword(s):  
Field Data ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Speed Estimation ◽  
Highway Capacity ◽  
Estimation Techniques ◽  
Highway Capacity Manual ◽  
Planning Models ◽  
Speed Flow ◽  
Simulation Results

Improved speed-estimation techniques for planning applications were developed and tested. Comparisons with field data and simulation results indicate that the recommended techniques provide better accuracy and consistency with the procedures contained in the 1994 update of the Highway Capacity Manual. These speed-estimation techniques will improve the accuracy of long-range transportation planning models for predicting travel time, delay, and air-pollutant emissions.

Growth, Metamorphosis and Energy Conversion in the Larvae of the Prawn, Palaemon Serratus

1969 ◽  
Vol 49 (1) ◽  
pp. 77-96 ◽  
Author(s):  
M. R. Reeve
Keyword(s):  
Energy Conversion ◽  
Larval Growth ◽  
Energy Conversion Efficiency ◽  
Variable Number ◽  
Larval Stages ◽  
Length Increase ◽  
History Of ◽  
The Mean ◽  
The Individual ◽  
Very High

The life-history of the larva of the prawn Palaemon serratus (Pennant) was studied in the laboratory and found to comprise a variable number of stages, dependent on feeding level and other factors. Larval moulting frequency was relatively constant at 3-day intervals, and could be followed in a population by daily examination for exuvia moult-casts. Length increase at each moult progressed arithmetically, and the highest mortalities occurred during metamorphosis. Consumption of Anemia nauplii by each larva rose from 30 to 400 per day. Populations of isolated animals (i.e. when cannibalism was excluded) were inspected daily and the exact number and duration of larval stages determined. Survival through metamorphosis was very high (over 85%) at both high and low feeding levels, although at the latter the larvae passed through more stages with more erratic duration times. At the end of the experiment, when all the larvae had metamorphosed, the mean dry weights at the high and low feeding levels were 7.7 and o.6 mg respectively. Larval stages could not be positively identified morphologically after stage III unless the history of the individual in question was known. It is suggested that the number of larval stages in the sea may also be very variable and difficult to determine.Energy-conversion efficiency was calculated from food uptake measurements and larval growth estimations, and was found to be 50–60% during most of the larval life, falling to 35% when the early post-larvae were taken into account.

How Reliable are Growth Back-Calculations Based on Otoliths?

1990 ◽  
Vol 47 (11) ◽  
pp. 2219-2227 ◽  
Author(s):  
Steven E. Campana
Keyword(s):  
Somatic Growth ◽  
Growth Effect ◽  
Fish Otolith ◽  
Stochastic Error ◽  
Individual Fish ◽  
Back Calculation ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Slow Growing

Growth back-calculations from otoliths assume that the relationship between fish and otolith length is linear through time. The final (or observed) individual fish-otolith ratios are then combined to prepare a fish-otolith regression for the population, upon which the subsequent back-calculations are based. However, recent studies have demonstrated that the fish:otolith size ratio varies systematically with somatic growth rate, resulting in relatively large otoliths in slow-growing fish. Such a growth effect will result in a fitted fish-otolith regression which differs significantly from that of the mean of the individual fish-otolith slopes. Fraser–Lee growth back-calculations made from such a regression consistently underestimate previous lengths at age. The bias may explain the apparent ubiquity of Lee's phenomenon. Back-calculation bias was eliminated through use of an algorithm defining individual fish-otolith trajectories and a biologically determined, rather than a statistically estimated, intercept. Adaptations of the biological intercept back-calculations procedure accurately predicted previous lengths in the presence of both stochastic error and time-varying growth rates. When used to reevaluate some published back-calculations, the biological intercept procedure resulted in more accurate values than those previously estimated, and reduced or eliminated the presence of Lee's phenomenon.

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