The paper aims to test operating speed models for curve sections on local two lane rural roads. In the beginning, the most important national and international models, which enable to calculate operating speed, are summed up. The form of the prediction models and number of variables used in each of them vary considerably. The most common operating speed models, proposed by many researchers of different countries, provide V85 as a function of the Degree of Curvature (DC) or of the Curvature Change Rate of the single curve (CCRs). All operating speed models, considered in this paper, are developed through regression analysis of collected speeds of free passenger cars. Afterward speed data are recorded on local curves. Different constraints have been imposed to select curve sites: rural area, relatively low traffic volume, marked and paved roadways with constant lane width, no stop control or intersections near to curve, the design speed ranges from 60 km/h to 100 km/h and the general speed limit is 90 km/h (in accordance with the “Italian Road Code”), longitudinal grades ≤ 5%. Subsequently, the most important national and international models, which have been gathered preceding, are applied on chosen curve sections, in order to calculate V85. Speed surveys are compared with the results of the models application. The article includes also a summary of the data collected and the results of a statistical analysis showing speed trends. The target of the paper is to verify on local roads the applicability of the existing speed models in order to implement them in the following step of the research work.

Local Tests of The Operating Speed Models for Curves

PIRAS, CLAUDIA;PINNA, FRANCESCO
2007-01-01

Abstract

The paper aims to test operating speed models for curve sections on local two lane rural roads. In the beginning, the most important national and international models, which enable to calculate operating speed, are summed up. The form of the prediction models and number of variables used in each of them vary considerably. The most common operating speed models, proposed by many researchers of different countries, provide V85 as a function of the Degree of Curvature (DC) or of the Curvature Change Rate of the single curve (CCRs). All operating speed models, considered in this paper, are developed through regression analysis of collected speeds of free passenger cars. Afterward speed data are recorded on local curves. Different constraints have been imposed to select curve sites: rural area, relatively low traffic volume, marked and paved roadways with constant lane width, no stop control or intersections near to curve, the design speed ranges from 60 km/h to 100 km/h and the general speed limit is 90 km/h (in accordance with the “Italian Road Code”), longitudinal grades ≤ 5%. Subsequently, the most important national and international models, which have been gathered preceding, are applied on chosen curve sections, in order to calculate V85. Speed surveys are compared with the results of the models application. The article includes also a summary of the data collected and the results of a statistical analysis showing speed trends. The target of the paper is to verify on local roads the applicability of the existing speed models in order to implement them in the following step of the research work.
2007
978-88-8207-260-5
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11584/97633
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact