A road safety approach for a new revision of the portuguese design guidelines

Abstract

The Portuguese road design guidelines have undergone periodical revisions, aiming at updating technical aspects of the geometric design of road elements and enlarging the field of their application to various types of roads and intersections. The National Laboratory for Civil Engineering (LNEC), through its Transportation Department, has provided scientific and technical support and advice to the road administrations along this process. At the present stage, a proposal made by LNEC points out to the need for a thorough reformulation of the whole set of documents which are currently being used in Portugal as road design guidelines, in order to introduce a greater integration among them, and new technical advances based on scientific ground. A strategy to carry out that reformulation is being followed, which involves the setting up of an encompassing framework centred in a so called “base document” which contains common concepts and technical indications to which all the guidelines for specific types of roads must comply with. In this paper a presentation is made on the main characteristics of the said “base document” prepared by LNEC, as well as the rationale underlying the introduction of a road safety approach into not only the conceptual frame but also the definition of road geometric design parameters and acceptable limit values, more closely related to the human component, which are derived, for example, from the assessment of driver’s behaviour characterization, using the results of a large number of measurements in Portuguese and other European road networks.