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Record W2064471118 · doi:10.1139/l02-093

Stochastic nature of freeway capacity and its estimation

2002· article· en· W2064471118 on OpenAlexvenueno aff
Abishai Polus, M. A. Pollatschek

Bibliographic record

VenueCanadian Journal of Civil Engineering · 2002
Typearticle
Languageen
FieldEngineering
TopicTraffic control and management
Canadian institutionsnot available
Fundersnot available
KeywordsIntersection (aeronautics)Highway Capacity ManualPercentileFlow (mathematics)Distribution (mathematics)Traffic flow (computer networking)StatisticsSelection (genetic algorithm)RegressionMathematicsEnvironmental scienceComputer scienceEconometricsTransport engineeringEngineeringLevel of serviceMathematical analysisGeometry

Abstract

fetched live from OpenAlex

The main purpose of this study was to investigate the meaning of freeway capacity, in particular to explore its stochastic nature and to estimate its distribution. The evaluation is based on traffic data from three busy urban freeway sections over 3 full days. Momentary capacity is defined as the intersection of the best-fit regression lines calculated for the dense- and unstable-flow regimes close to the maximum flow. An algorithm was developed for the selection of the relevant pairs for each regression line and is discussed. It is argued that momentary capacity values are stochastic in nature and distributed according to the shifted gamma distribution. Estimation of the parameters of this distribution for the three urban freeway sections is studied. It is proposed that the 5th percentile of the distribution, found to be approximately 2330 vehicles per hour per lane for the prevailing conditions of the basic section, could be adopted as the representative design value of capacity. Another conclusion is that the average distribution of capacities for all three through lanes is relatively close to the distribution of capacities in the middle lane.Key words: freeway flow, capacity, flow breakdown, dense flow, unstable flow.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.022
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.008
Threshold uncertainty score0.015

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0030.022
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0020.001
Science and technology studies0.0000.001
Scholarly communication0.0010.002
Open science0.0010.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.006
GPT teacher head0.150
Teacher spread0.144 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations50
Published2002
Admission routes1
Has abstractyes

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