Optimizing Geometric Design of Standard Turboroundabouts

Džambas, Tamara; Dragčević, Vesna; Korlaet, Željko

doi:10.1007/s12205-020-1689-3

Cited by 5 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, all the existing design guidelines listed in Table 1 [5,15,16,19,24,27,28,32] apply to roundabouts with approaches oriented to each other at a right angle. Similar comments can be noted with regard to the publications shown in Table 1, concerning the analysis of the driving corridors of selected design vehicles and, consequently, the lane widths of the turbo-roundabout and the entry and exit radii [24,25,29,30,33,34].…”

Section: Country Year Brief Overview Of Recommendations In Selected G...supporting

confidence: 70%

“…Because the current intersection does not have a north approach, thi article assumes a case study analysis and proposes a north approach with an 8 m-wid splitter island in accordance with the current Polish design guidelines for conventiona roundabouts [39]. Considering that most of the above-mentioned design guidelines fo turbo-roundabouts assume the use of splitter island widths of 2-3 m [5,15,16,19,24,27,28,32] and taking into account the detailed swept path analyses describe in [34], related to offsetting the roundabout entry lane relative to the approach axis, roundabout with varying widths and different shapes of the splitter islands at each ap proach was chosen specifically for the analyses described in this article. The alignment of the approach axes at the location selected for the described analyses of the proposed turbo-roundabout.…”

Section: Study Areamentioning

confidence: 99%

“…Taking into account the observations described in Section 3.2, regarding the need for the provision of mountable apron areas on all approaches, lane separator and road marking line encroachments, and considering the research conclusions formulated in publications [24,25,29,33,34], successive iterations as regards the outer lane widths and the values of the entry and exit radii were applied in the swept path analyses described in this article in Stage III. The geometry of the roundabout was designed as follows: (a) First, the outer circulatory lane was incrementally widened until the DV1 swept path requirement for right-turning movements from the side approaches was satisfied, which means the vehicle path no longer encroached on the road marking lines; (b) next, the edges of the splitter islands were adjusted by iterative specification of the entry and exit radii.…”

Section: An Analysis Of the Swept Paths On The Basic Turbo-roundabout...mentioning

confidence: 99%

See 2 more Smart Citations

Design of Turbo-Roundabouts Based on the Rules of Vehicle Movement Geometry on Curvilinear Approaches

Sołowczuk,

Benedysiuk

2023

Sustainability

View full text Add to dashboard Cite

The construction of turbo-roundabouts is an increasingly frequent choice when it comes to improving flow capacity and traffic safety at road intersections. The existing design guidelines, as a rule, give parameters for turbo-roundabouts with approaches set at right angles to each other. The article presents turbo-roundabout design methods, taking into account swept path analyses of the chosen design vehicles when the approach legs are curvilinear and oriented to each other at a non-right angle. Based on the analysis of three different design vehicles, it was proven that their swept paths have a major influence on the geometrical parameters of the roundabout and, consequently, on the land take area, i.e., they can significantly impact the project’s construction costs. In the case of curvilinear approaches, which are oriented to each other at a non-right angle, it is impossible to impose on the designer specific values of the circulatory lane widths and the entry and exit curve radii as they depend primarily on the chosen design vehicle. The aim of the article was to demonstrate that in the case of the curvilinear approach on the Basic type turbo-roundabout, the design process should include the swept path analysis for the chosen design vehicle for each of the approaches. This should lead to the design of wider swept paths and higher curve lane divider entry and exit radii.

show abstract

Section: Country Year Brief Overview Of Recommendations In Selected G...supporting

confidence: 70%

Section: Study Areamentioning

confidence: 99%

Section: An Analysis Of the Swept Paths On The Basic Turbo-roundabout...mentioning

confidence: 99%

See 1 more Smart Citation

Design of Turbo-Roundabouts Based on the Rules of Vehicle Movement Geometry on Curvilinear Approaches

Sołowczuk,

Benedysiuk

2023

Sustainability

View full text Add to dashboard Cite

show abstract

“…The parallel splitter island on the main approach legs was initially 2 m wide. In the case under analysis, the parallel splitter islands requirement of [1,[31][32][33][34] did not, unfortunately, ensure the required swept path. In the subsequent iterative steps of the design process, the DV1 swept path was ensured only when 1:15 tapers were adopted for all the roundabout elements (i.e., splitter islands and lane edges).…”

Section: "Flattened" Turbo-roundabout Featuring a 024-m-wide Separati...mentioning

confidence: 99%

Design Study for the Construction of Turbo Roundabouts under Constrained Site Conditions

Sołowczuk,

Majer

2023

Sustainability

View full text Add to dashboard Cite

Turbo-roundabouts are one of the most frequently recommended road junction design options when it comes to increasing traffic capacity and traffic safety. This is in particular true of suburban areas, with dominant traffic flow on the main road and moderate traffic flow on the side road. Other intersections handling local traffic and considerably constricting the availability of space are usually located in the vicinity of such intersections. Another factor contributing to the limited availability of land for construction in these locations is the presence of surrounding residential housing. Then, choosing the suitable turbo-roundabout type becomes the main issue. The article presents a case study for the selection of a type of turbo roundabout under the conditions of considerably constricted land availability based on the analysis of the provision of a swept path for the chosen design vehicles. The article considers the standard egg-type turbo-roundabouts, “look-a-like” type turbo-roundabouts, non-standard “flattened” turbo-roundabouts and ellipse-based roundabouts, with non-standard geometries of the truck apron and central island. For each of the analysed roundabout types, setting-out methods were described in detail, allowing the designer to quickly select a type of roundabout suitable for the specific constrained site conditions. This article analyses the applicability of non-standard turbo roundabouts for three area types: LUDA low urbanisation degree area, BA built-up area and CDA highly commercially developed area along the side road, wherever standard roundabouts are not practicable due to constraints imposed by existing buildings, canals or any other obstacles found at the project site.

show abstract

“…Minimal safety lateral widths of 0.25 m were ensured along the elevated splitter islands in every roundabout scheme, according to the instructions given in [9,21]. At the same time, safety lateral widths of at least 0.50 m were ensured along the outer roundabout radius, according to the instructions given in [22]. Fifty simulations were conducted, and in total, 200 design vehicle body and chassis envelopes were created.…”

mentioning

confidence: 99%

The Design Vehicle Steering Path Construction Based on the Hairpin Bend Geometry—Application in Roundabout Design

Ahac

Džambas

et al. 2022

Applied Sciences

View full text Add to dashboard Cite

A prerequisite for a well-designed roundabout is the definition of the design vehicle movement geometry and its turning envelopes. This is because kinematic and dynamic requirements lose their importance due to low driving speed. In this paper, the investigation of the deviations of design vehicle steering paths for straight passage through the roundabout constructed according to the two approaches is presented. The first approach (A-1) includes the application of short, straight lines between the adjacent arcs on the path, and the second (A-2) implies the application of consecutive circular arcs. A computer simulation of vehicle movement was conducted using the Autodesk Vehicle Tracking 2020 software. The results showed that A-2, a faster and simpler approach, is applicable with caution, as the resulting turning envelopes derived from this approach are more offset from the roundabout centers compared to the A-1 approach. A total of 72% of right-hand-side path and resulting right-hand-side design vehicle body and chassis turning envelope deviations were between 0.00 and 0.15 m, 27% were over 0.15 m, and 7% were over 0.25 m. This results in larger roundabout entry and exit widths as well as the need for large lateral clearances for entries and exits on roundabouts where heavy pedestrian traffic on sidewalks is expected. The noted offset of left-hand-side design vehicle trajectories on the circulatory roadway (which was mostly between 0.05 and 0.15 m) could have a positive impact on the deflection around the central island.

show abstract

Optimizing Geometric Design of Standard Turboroundabouts

Cited by 5 publications

References 26 publications

Design of Turbo-Roundabouts Based on the Rules of Vehicle Movement Geometry on Curvilinear Approaches

Design of Turbo-Roundabouts Based on the Rules of Vehicle Movement Geometry on Curvilinear Approaches

Design Study for the Construction of Turbo Roundabouts under Constrained Site Conditions

The Design Vehicle Steering Path Construction Based on the Hairpin Bend Geometry—Application in Roundabout Design

Contact Info

Product

Resources

About