Tamara Džambas

Design of Turbo Roundabouts Based on the Rules of Vehicle Movement Geometry

This paper describes a turbo roundabout design procedure based on the rules of design vehicle movement geometry. Previous studies carried out on various junction types have shown that this design approach ensures the usage of optimal roundabout element dimensions as well as safety and comfort during driving. A five-step design procedure is suggested, including a detailed description of relevant influential parameters. They are choosing a design vehicle, implementing the initial roundabout scheme on which the vehicle swept path is analyzed, choosing a method of assigning input parameters for swept path requirements testing procedure, choosing optimal design elements of a standard turbo roundabout, and fastest path vehicle speed analysis.

Geometric design of turbo roundabouts

Turbo roundabouts are lately a more common choice in designing multilane roundabouts. First guidelines for geometric design of this particular roundabout layout were developed by a Dutch Information and Technology Platform CROW in 2008. Soon after, a number of European countries began to develop their own regulations on turbo roundabouts, adjusted to their traffic cultures and their local conditions. In order to present the diversity of design approaches for turbo roundabout planning in various European regions, comparative analysis of turbo roundabout design procedures described in Slovenian technical specifications, Serbian design manual, German working document, and Croatian and Dutch guidelines is made. Relevant influential parameters used in these procedures are commented. Study presented in this paper may contribute to the success of turbo roundabout planning procedure.

Sight distance evaluation on suburban single-lane roundabouts

U radu se obrađuje problematika preglednosti na izvangradskim kružnim raskrižjima.mDan je pregled postupaka određivanja potrebne preglednosti, prikazanih u propisima, normama i smjernicama koji vrijede u Austriji, Francuskoj, Hrvatskoj, SAD-u, Srbiji i Svicarskoj. Detaljno su prikazani utjecajni parametri i postupci određivanja polja preglednosti definirani u razmatranim dokumentima. Istaknuta je raznolikost u pristupima ispitivanju preglednosti te je dan komentar rezultata ispitivanja provedenih na teorijskom primjeru izvangradskog kružnog raskrižja.

Ispitivanje preglednosti na izvangradskim jednotračnim kružnim raskrižjima

U radu se obrađuje problematika preglednosti na izvangradskim kružnim raskrižjima.mDan je pregled postupaka određivanja potrebne preglednosti, prikazanih u propisima, normama i smjernicama koji vrijede u Austriji, Francuskoj, Hrvatskoj, SAD-u, Srbiji i Svicarskoj. Detaljno su prikazani utjecajni parametri i postupci određivanja polja preglednosti definirani u razmatranim dokumentima. Istaknuta je raznolikost u pristupima ispitivanju preglednosti te je dan komentar rezultata ispitivanja provedenih na teorijskom primjeru izvangradskog kružnog raskrižja.

The Influence of Visibility Conditions in Horizontal Road Curves on the Efficiency of Noise Protection Barriers

Abstract Ensuring sufficient visibility on planned roads by sight distance testing is an integral part of every project, but problems with visibility can emerge when noise barriers are erected on existing roads. Namely, in order to provide sufficient noise protection, high noise barriers are often placed at minimum distance from the carriageway edge, and additional visibility testing in most cases is not carried out. Research described in this paper consists of stopping sight distance tests conducted by means of specialized road design software MX Road, and noise barrier optimization conducted by means of specialized noise prediction software LimA using static noise calculation method RLS 90. The aim of this research is to establish whether the required stopping sight distance on road sections where minimum design parameters are applied can be achieved if the noise barrier is placed at minimum distance from the carriageway edge, and to establish whether the optimized dimensions of planned noise protection barrier will change if the barrier is placed on larger distance from the noise source, which is, in this case, the existing road.