Feasibility of 2+1 Roads on Alberta Rural Highway Network
Bibliographic record
Abstract
Over the last twenty years, European countries have built several thousand kilometres of in which an existing or new 13 to 14 metre wide, paved two-lane road segment (8 to 20 kilometres long) is re-striped into three traffic lanes, with the centre lane used as the passing lane in alternate directions. The European 2+1 roads serve traffic volumes from 6,000 AADT to 30,000 AADT. Many are quasi-freeways with grade separated access. At-grade intersections are discouraged; where they cannot be avoided, they are, as a rule, placed in the transition zone between adjacent alternating passing lanes. From the European experience, it is evident that the 2+1 road design aids in the economic, environmental and social sustainability of roads, because it: (a) reduces fuel consumption by improving the road's Level of Service by reducing platooning and congestion; (b) helps defer or avoid the need for road twinning; and (c) reduces the rate of fatal and serious injury collisions by an average 25 percent. The European 2+1 road design has not yet been implemented in North America. The objective of the study reported in this paper was to assess the feasibility of implementing the European 2+1 road concept on the rural Alberta highway network managed by Alberta Transportation (AT), and if found feasible, to propose a small number of segments for implementation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".