Alternative Types of Roundabouts

Tollazzi, Tomaž

doi:10.1007/978-3-319-09084-9

Cited by 46 publications

(57 citation statements)

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“…It is useful to remember that the choice of the turbo roundabout also depends on the predominant direction of the main traffic flow. In effect, the predominant direction of the main traffic flow is a criterion for the choice of the turbo roundabout [1].…”

Section: Microsimulation Inputsmentioning

confidence: 99%

“…Building on previous research where the issue of alternative roundabouts was investigated [1,2], microsimulation is used to simulate traffic operations at roundabouts with standard and newer layouts at various levels of traffic volume. Performance measures include emissions and level of service, as well as measures of safety, including conflicts and speeds, both estimated from trajectories generated in the microsimulation.…”

Section: Introductionmentioning

confidence: 99%

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Using Microsimulation to Evaluate Safety and Operational Implications of Newer Roundabout Layouts for European Road Networks

et al. 2017

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"Standard" roundabouts, for example those designed in some European countries, can often be characterized by low levels of safety or capacity and a high degree of sustainability. Given the proliferation of newer layouts, it is of interest to explore whether design practices could be improved by capitalizing on the experience gained internationally. Operational aspects of some of these designs have been explored previously, but there is a need to compare both the operational and safety performance of new designs to that of standard roundabouts. The objective of this paper is to evaluate the safety and operational implications of various potential alternatives to the standard roundabouts that proliferate in Europe and elsewhere. Microsimulation is used to simulate traffic operations at roundabout layout alternatives at the same levels of volume to capacity (V/C) ratio and also with the same traffic flow. Operational performance measures include the common level of service parameters, while measures of safety are based initially on time to collision (TTC) values. Threshold values of TTC were then applied in defining conflicts that are used for crash-based safety evaluation by applying crash-conflict models estimated in published research. Interesting insights were revealed, suggesting that the newer layouts should be considered where warranted by cost-benefit considerations.

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Section: Microsimulation Inputsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Using Microsimulation to Evaluate Safety and Operational Implications of Newer Roundabout Layouts for European Road Networks

et al. 2017

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“…In some other regions, for instance in Czech Republic, such behaviour is allowed i.e. long vehicles are, because of insufficient entry, exit and circulatory lanes widths, allowed to drive partially in neighbouring lanes [39].…”

Section: Horizontal Swept Path Analysismentioning

confidence: 99%

Geometric design of turbo roundabouts

2017

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Subject reviewTurbo 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. Keywords: comparative analysis; geometric design; guidelines; influential parameters; turbo roundabouts Geometrijsko oblikovanje turbokružnih raskrižjaPregledni rad Turbokružna raskrižja su u posljednje vrijeme sve češći izbor pri projektiranju višetračnih kružnih raskrižja. Prve smjernice za geometrijsko oblikovanje ovog posebnog tipa kružnog raskrižja razvijene su od strane nizozemskog istraživačkog centra CROW u 2008. Ubrzo nakon toga, nekolicina europskih zemlja započela je s razvojem vlastitih smjernica, prilagođenih njihovim prometnim navikama i lokalnim uvjetima. Kako bi se dobio uvid u raznolikost pristupa oblikovanju turbokružnih raskrižja u različitim europskim zemljama, provedena je komparativna analiza postupaka njihova oblikovanja opisanih u slovenskim tehničkim specifikacijama, srpskom priručniku, njemačkom random dokumentu, te hrvatskim i nizozemskim smjernicama. Komentirani su relevantni utjecajni parametri koji se u navedenim postupcima koriste. U radu prikazano istraživanje doprinijelo bi uspješnosti provođenja postupka geometrijskog oblikovanja turbokružnih raskrižja.

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“…This layout represents an innovative arrangement of conventional multi-lane roundabout that has altered intersection design in some European countries (1).…”

Section: Introduction and Objectivesmentioning

confidence: 99%

Turboroundabouts Along Corridors: Analysis of Operational and Environmental Impacts

Fernandes

Rouphail

Coelho

2017

Transportation Research Record: Journal of the Transportation R

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The number of turbo-roundabouts constructed in Europe has grown steadily in the past decade. While there has been extensive work on the operational and environmental impacts of isolated turbo-roundabouts, research on closely-spaced turbo-roundabouts along corridors is somewhat lacking.The objective of this research is to evaluate the impact of turbo-roundabout corridors on both traffic performance and emissions. The research has three major thrusts: 1) to identify the hotspot emission locations along turbo-roundabout corridors; 2) to compare the overall performance of turbo-roundabout corridors against conventional two-lane roundabouts on arterials; 3) to address the integrated effect of geometric and operational characteristics of turboroundabout corridors on carbon dioxide, carbon monoxide, nitrogen oxides and hydrocarbons emissions.Vehicle activity along with traffic flow data were collected from three turbo-roundabout corridors in the Netherlands. Site-specific operations were analyzed using microscopic traffic and emissions platforms (respectively, VISSIM and Vehicle Specific Power -VSP).The results showed that emission hotspots along these corridors occurred in the segments located just downstream of the turbo-roundabout, both in absolute terms (more than 30% of total emissions) and per unit distance. It was also found that the implementation of two-lane roundabout corridors outperformed the turbo-roundabout corridors in terms of vehicle emissions, however the differences were not statistically significant (p-value<0.05). Data analysis indicated that an additional decrease in corridor's emissions (4-11%, depending on the pollutant) may be reached by altering the spacing (from 180 to 240 m) between two-closely spaced turboroundabouts.

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Alternative Types of Roundabouts

Cited by 46 publications

References 0 publications

Using Microsimulation to Evaluate Safety and Operational Implications of Newer Roundabout Layouts for European Road Networks

Using Microsimulation to Evaluate Safety and Operational Implications of Newer Roundabout Layouts for European Road Networks

Geometric design of turbo roundabouts

Turboroundabouts Along Corridors: Analysis of Operational and Environmental Impacts

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