Notice bibliographique
Résumé
This paper presents the results of research by the Queensland Department of Main Roads on sight distance issues as related to existing roads. The research was carried out in conjunction with the development of the Department's Road Planning and Design Manual. There are many sections of road in Queensland that have generally suitable horizontal geometry by virtue of the design practices or standards that were used when they were designed in the 1940's, 1950's and early 1960's. However, the vertical geometry often contains some crest vertical curves that are deficient in terms of current design standards: standards that have existed since the mid 1960's. At the same time, the vehicle speeds on many of these roads are significantly different from those assumed at the time of design. But, there is usually no accident history at the places that have deficient sight distance. Given the satisfactory operation of these roads, restoration has usually been favored over realignment in an era of restricted road funding. However, the design process must also ensure that the restoration does not change driver perceptions of the road to the extent that operation is compromised anywhere. Restoration is defined as works that improve the cross section and riding quality of a road but do not involve any change in the horizontal or vertical alignment. This situation is common to most developed countries. The effect of sight distance on existing roads has been well researched overseas; in particular in the USA and Canada. This has been researched from as early as 1953 when it was found that drivers were overdriving crests that had been designed for the lower performance that vehicles had some 20 to 40 years earlier. Together, the USA and Canadian research indicates that there does not seem to be a problem as long as there is about 100m of sight distance and there are no intersections. The Canadian Design Manual is the only known 'primary road design manual' that formally recognizes this factor for restoration treatments for roads. In the USA, restoration is covered in a separate document to the primary AASHTO policy on geometric design. Overseas research to determine a link between accident rates and sight distance has been largely inconclusive. The Queensland Department of Main Roads formalized the use of sight distance for crests on existing roads in 1981. As in the USA, this was done in a separate document to the primary design guide. This used a reduced maneuver sight distance model. However, no explanation of the key maneuver time parameter was given. Nor was the operation of large commercial vehicles explicitly covered. Given the increasing need to be able to defend road geometry, this paper proposes how sight distance may be defended in terms of the intent of the sight distance standards for a new road. This is because any case of sight distance will inevitably be compared with the standard for a new road (in other words, what is done now). An extreme case of the maneuver sight distance model is used as an example.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».