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A GPSS/360 Computer Model for Simulation of Automobile Traffic at Road IntersectionsGolovcsenko, Igor V. 01 January 1974 (has links) (PDF)
No description available.
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Operational and environmental comparisons between left-turn bypass, diverging flow and displaced left-turn intersection designsUnknown Date (has links)
The rapidly and significantly growth of the population in the United States has caused expansion of the urban areas to accommodate more residential facilities.. Thus, the demand for more efficient intersection designs is a high priority, as wasted fuel and travel time increases each year. A new method to solve the congestion issue is the creation of unconventional arterial intersection designs (UAID). The objective of this study is to compare the operational and environmental performance of three UAIDs called Left-turn Bypass, Diverging Flow, and Displaced Left-turn intersections. This study will evaluate the UAIDs in the isolated manner and then compare the intersections in a network using an existing corridor in the state of Florida. The microscopic simulation platform VISSIM v. 5.10 will be used to test different scenarios. The results indicated that the Displaced Left-turn consistently reports better results for average delay of less than 20 seconds per vehicle. / by Claudia Olarte. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
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Comparison of Various Methods to Compute Access Density and Proposing a Weighted MethodologySaxena, Meeta 06 November 2010 (has links)
This study aims to compare three distinct methods used to compute access density and provide a comprehensive weighted methodology to enable standardization for research and application in the future. Access density is a widely used concept that calculates the number of access points within a given distance and has been extensively applied to studies related to crash modeling, operational impact and planning.
Methods used in past research show that access density is computed differently by different studies and all studies do not include all access points. The weighted methodology proposed takes into account all access points including driveways, intersections and median openings and categorizes them into geometric combinations. Each geometric combination have potential number of conflict points which include diverging, weaving, merging and crossing movements depending on the type of access point. Weights were assigned to each geometry type based on these conflict point ratio.
In conclusion the study identifies and compares methods previously used to compute access density and accordingly, recommends a weighted methodology that includes all access points which can be used as a standard, universal measure all access density related studies including but not limited to safety impacts, operational impacts and planning guidelines.
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Cooperative Automated Vehicle Movement Optimization at Uncontrolled Intersections using Distributed Multi-Agent System ModelingMahmoud, Abdallah Abdelrahman Hassan 28 February 2017 (has links)
Optimizing connected automated vehicle movements through roadway intersections is a challenging problem. Traditional traffic control strategies, such as traffic signals are not optimal, especially for heavy traffic. Alternatively, centralized automated vehicle control strategies are costly and not scalable given that the ability of a central controller to track and schedule the movement of hundreds of vehicles in real-time is highly questionable. In this research, a series of fully distributed heuristic algorithms are proposed where vehicles in the vicinity of an intersection continuously cooperate with each other to develop a schedule that allows them to safely proceed through the intersection while incurring minimum delays. An algorithm is proposed for the case of an isolated intersection then a number of algorithms are proposed for a network of intersections where neighboring intersections communicate directly or indirectly to help the distributed control at each intersection makes a better estimation of traffic in the whole network. An algorithm based on the Godunov scheme outperformed optimized signalized control. The simulated experiments show significant reductions in the average delay.
The base algorithm is successfully added to the INTEGRATION micro-simulation model and the results demonstrate improvements in delay, fuel consumption, and emissions when compared to roundabout, signalized, and stop sign controlled intersections. The study also shows the capability of the proposed technique to favor emergency vehicles, producing significant increases in mobility with minimum delays to the other vehicles in the network. / Ph. D.
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Pre-signal study at an at-grade intersection with separate right-turn phaseTang, Hao 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Capacity waste happens when right-turn vehicles have right-of-way during a
separate right-turn phase and lanes (e.g., through lanes) of the same approach of
the intersection cannot discharge vehicles during that green phase. Right-turn traffic
consumes the capacity which otherwise could be provided to through traffic
movements at an at-grade signalized intersection. Therefore, it is widely considered
that it would lower intersection capacity and increase total delay (Lin, Machemehl,
Lee & Herman, 1984).
The pre-signal strategy proposed in this research is specifically designed to improve
this problem. The following aspects of this strategy were studied in this research,
- Capacity benefits of this strategy,
- Relationships between the capacity and the length of sorting area (the area
between the two signals),
- Signal timing of both main signal and pre-signal,
- Clearance time of the sorting area,
- Main signal phasing options
- Signal coordination between the main signal and the pre-signal,
- Utilization of the sorting area, and
- Pre-signal strategy performance in a simulated environment. The results of this study showed that right-turn movement benefits significantly from
this pre-signal strategy. For example, right-turn capacity can be doubled if a presignal
is installed on one through lane of an approach with one right-turn lane.
It was also found, the maximum approach capacity benefit is not affected
significantly by the length of the sorting area for a given green period. The optimal
green time and the available pre-signal green time for right-turn movement were also
derived in this research. Different main signal phasing options were studied and
compared. Phasing options which fit the proposed pre-signal strategy were found.
Recommended values for right-turn green time of both signals were given based on
different lengths of sorting area. The case study, which compared the performance of some critical movements at the
intersection with and without the proposed pre-signal system, confirms the results
concluded in this study.
A potential problem with this strategy when applied at a real intersection is that it
may confuse drivers. Drivers need to be educated and will need time to get familiar
with this signal control method. / AFRIKAANSE OPSOMMING: Beskermde regsdraaifases vir verkeer by gelykvlak seinbeheerde kruisings gebruik
die kapasiteit wat benut kon word deur deurbewegings. Dit verlaag interseksie
kapasiteit en totale oponthoud verhoog.
Die voorseinstrategie wat in die navorsing studie voorgestel word is spesifiek
ontwikkel om die probleem op te los of te verminder. Die volgende aspekte van die
strategie is ondersoek in die navorsingsstudie:
- Kapasiteitsvoordele van die strategie.
- Die verhouding tussen die kapasiteit en die lengte van die sorteringsarea (die
area tussen die twee seine).
- Seintydstoedeling van beide die hoofseinfase en die voorseinfase.
- Ontruimingstyd van die stoorarea.
- Hoofseinfaseopsies.
- Seinkoordenasie tussen die hoofsein en die voorsein.
- Benutting van die sorterings area, en
- Voorseinstrategieprestasie in ‘n gesimuleerde omgewing. Die resultate bewys dat die regsdraaibeweging grootliks bevoordeel word nadat die
voorseinstrategie ingestel is. Byvoorbeeld, regsdraaikapasiteit kan verdubbel word
as ‘n voorseinfase ingestel word op een van die deurlane tesame met ‘n enkele
regsdraailaan.
Daar is ook gevind dat die kapasiteit nie grootliks beinvloed word deur die lengte van
die stoorgebied nie. Die optimale groentyd en die beskikbare voorsein groen tyd vir
die regsdraaibeweging is ook afgelei in die navorsing. Verskillende
hoofseinfaseopsies is bestudeer en vergelyk. Faseringsopsies vir die voorgestelde
voorseinstrategie is gevind. Voorgestelde waardes vir regsdraaigroentyd van
voorseine en hoofseine is bereken om kapasiteit te verbeter, gebasseer op
verskillende lengtes van die stoorarea.
Die gevallestudie wat die prestasie op ‘n aanloop met en sonder die voogestelde
voorseinstrategie vergelyk, bewys resultate wat ooreenstem met die bevindinge in
die studie. Die verwagte probleem met die voorseinstrategie, wanneer dit ingestel word by ‘n
werklike interseksie, is verwarring van die bestuurders. Bestuurders sal opgevoed
moet word en sal tyd nodig hê om gewoond te raak aan die voorseinmetode.
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Lane-based optimization method for traffic signal designWong, Chi-kwong., 黃志光. January 2004 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
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An investigative report on interchange zone problems of the non-toll I-70 freeway in KansasHu, Shu Dean. January 1975 (has links)
Call number: LD2668 .P7 1975 H8
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Safety Effectiveness and Safety-Based Volume Warrants of Right-Turn Lanes at Unsignalized Intersections and Driveways on Two-Lane RoadwaysAle, Gom January 2012 (has links)
Disagreements regarding to what degree right-turn lanes improve or worsen the safety of intersections and driveways provided the motivation and the need for this study. The objectives of this study were to: a) carry out an in-depth study to determine the safety impacts of right-turn movements in different contexts, and b) develop safety-based volume warrants for right-turn lanes if safety indeed improves. Lack of adequate study on the applicability of past warrants and guidelines for the specific context of right-turn movements made from major uncontrolled approaches at unsignalized intersections, and particularly driveways, on two-lane roadways provided the scope for this study. Five-year historical data of statewide traffic crashes reported on Minnesota's twolane trunk highways were analyzed using binary/multinomial logistic regressions. Conflicts due to right turns were analyzed by fitting least squares conflict prediction models based on the data obtained from field surveys and traffic simulations. The safety impacts of rightturn lanes were determined through crash-conflict relationships, crash injury severity, and crash and construction costs. The study found that the probabilities of right-turn movement related crash ranged from 1.6 to 17.2% at intersections and from 7.8 to 38.7% at driveways. Rear-end, samedirection- sideswipe, right-angle and right-turn crash types constituted 96% of right-turn movement related crashes. Rear-end crash probabilities varied from 13.7 to 46.4% at approaches with right-turn lanes and from 37.9 to 76.9% otherwise. The ratios of rearend/ same-direction-sideswipe crashes to conflicts were 0.759 x 10-6 at approaches with right-turn lanes and 1.547 x 10-6 otherwise. iv Overall, right-turn lanes reduced right-turn movement related crash occurrences and conflicts by 85% and 80%, respectively. Right-turn lanes also reduced crash injury severity, hence, reducing the economic cost by 26%. Safety benefits, in dollars, realized with the use of right-turn lanes at driveways were 29% and 7% higher compared to those at intersections at low and high speed conditions respectively for similar traffic conditions. Depending on roadway conditions, interest rate and construction costs, the safety-based volume thresholds ranged from 3 to 200 right turns per hour during the design hour at intersection approaches, and from 2 to 175 right turns at driveway approaches. / Civil and Environmental Engineering / College of Engineering
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Investigation of the impact of junctions on the frequency of road crashes in urban areasUnknown Date (has links)
The huge financial and societal cost associated with traffic crashes and the fact
that more than half of them occur at junctions, revealed the need for further research in
the field of junction safety. This research aims to investigate the quantitative impact of
junctions in relation to other selected parameters, on the frequency of road crashes in
urban areas in the State of Florida. Mathematical models were developed with the use of
loglinear analysis method for different traffic volumes in and out of junction. In addition,
sensitivity analysis was performed in order to better understand the impact of selected
parameters to the total number of crashes. The analysis has led to several conclusions
such as that angle and left turn collisions have much higher probability of occurrence at
junctions and that crashes which occur at junctions are much more probable for low and
medium volumes compared to no-junctions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Influência dos veículos pesados na capacidade de interseções rodoviárias / Influence of heavy vehicles on the capacity of rural intersectionsDemarchi, Sergio Henrique 23 January 1995 (has links)
Este trabalho avalia a influência de veículos de grande porte na capacidade de interseções rodoviárias em nível não semaforizadas, verificando as variações no comportamento de caminhões e ônibus durante manobras de cruzamento, em função de seu comprimento e de sua relação potência/peso. Foram realizadas análises das distribuições dos tempos de cruzamento e da aceitação de \"gaps\" por diferentes tipos de veículos, sendo utilizados modelos Logit para representar o comportamento desses veículos nos cruzamentos. Estes modelos serviram como base na elaboração de um simulador, para determinar a capacidade potencial das interseções e para calcular os fatores de conversão de veículos de grande porte em veículos de passageiro. / This study assesses the influence of heavy vehicles on the capacity of unsignalized rural intersections. This is done through the study of vehicle behavior during crossing maneuvers that can be attributed to length and power-to-weight ratio. Crossing time distributions and gap acceptance of diferent types of vehicles were analysed, and Logit models were used to represent their behavior. These models and a simulation model were used to determine the potencial capacity of intersections and to calculate factors to convert heavy vehicles into passenger vehicles.
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