The accident rate at an intersection is one attribute used to evaluate the hazard associated with the intersection. Two techniques traditionally used to make such evaluations are the rate-quality technique and a technique based on the confidence interval of classical statistics. Both of these techniques label intersections as hazardous if their accident rate is greater than some critical accident rate determined by the technique. An alternative technique is one based on a Bayesian analysis of available accident number and traffic volume data. In contrast to the two classic techniques, the Bayesian technique identifies an intersection as hazardous based on a probabilistic assessment of accident rates. The goal of this thesis is to test and compare the ability of the three techniques to accurately identify traffic intersections known to be hazardous. Test data is generated from an empirical distribution of accident rates. The techniques are then applied to the generated data and compared based on the simulation results.

M.Ing. (Mechanical Engineering) / The purpose of this study was to investigate the accuracy of SOAP84-simulations of delay and percentage stops at isolated signalized intersections. In the application, capacity was distinguished in terms of lane configuration only. Results at the intersections showed SOAP overestimating both delay and percentage stops by as much as 100%. It is recommended that the same investigations be repeated with more accurate information on the capacity of the intersections.

Traditional intersections have always caused congestion, delay, and accidents. There are numerous geometric intersection designs that best fit each situation. This study performed an operational and safety comparison with unsignalized/signalized offset, Tintersections, a two-lane roundabout, and a modified roundabout to decrease the overall travel delay and increase the safety using a case study. Using data from a government source, all designs were tested in a calibrated micro simulation model and traffic signals were optimized using a signal optimization platform. Each design was tested with various balancing schemes, left turn percentages, and hourly volumes to determine the failure point. The unsignalized/signalized offset T-intersections, two-lane roundabout, and modified roundabout were compared by throughputs, travel delay, and travel time. After analysis, it was determined that the modified roundabout performed the best out of any design. All approaches had minimum travel delay while reducing the number of conflict points considerably with the modified roundabout. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

This study describes analytical model as one innovative way to simulate Light Rail Transit (LRT) operations and calculate vehicular, transit and person delays at LRT crossings through Microsoft Excel. Analytical model emulates LRT trajectories from field and use these trajectories to clearly define train and car phases through Visual Basic for Applications (VBA) logic, which is part of analytical model. Simulation of train trajectories and calculations of delays were done for different LRT strategies and estimated roadway condition, Testing and validation of analytical model were performed in one case study in Salt Lake City (UT). Results show that analytical model is capable of emulating LRT trajectories and estimating delay at isolated LRT crossing. However, analytical model is not capable of simulating different train strategies at two or more LRT crossings, at the same time. Finally, extracted strategy provides savings from $100.000 to $200.000 in study area, on annual basis for projected year. / by Nikola Mitrovic. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

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.

No description available.

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. 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.

No description available.

No description available.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Road traffic accidents have been a global concern facing all countries. Approximately 1.2 million people are killed annually as a result of traffic accidents and 50 million are injured. More than 90 percent of road fatalities occur in the developing world which has only 48 percent of the world’s registered vehicles. Beyond the problem of road fatalities, road traffic accidents result in disability and long term injury. They also cause considerable economic losses to victims and their families and damage properties and infrastructures. In South Africa, pedestrian fatalities account for about 40 percent of all road traffic accidents. Behaviour patterns of both pedestrians and motorists at pedestrian crossings are the main influential factors of pedestrian accidents. This study investigates behaviour patterns of pedestrians negotiating different types of crossing facilities in the town of Stellenbosch, in South Africa. A total number of 17 pedestrian crossings were selected for the study on the basis of their geometric and operational characteristics. Video-based observations together with on-street interviews were used to understand crossing behaviour patterns, namely pedestrian walking speed, pedestrian delay, gaze behaviour, pedestrian-vehicle conflicts, pedestrian compliance with road traffic rules and gap-acceptance behaviour. Results of the study showed that male pedestrians walk more than female pedestrians. The 15th percentile crossing speed for all pedestrians observed while crossing was found to be 1.13 m/s whereas the mean crossing speed was found to be 1.48 m/s. Demographic variables appeared to significantly influence pedestrian walking speed. Male and younger pedestrians exhibited higher walking speeds than female and older pedestrians. Pedestrian walking speed was also found to be affected by group size, encumbrance, type of pedestrian facility and distraction while walking. However, no effects of conflicts and the presence of a pedestrian refuge on pedestrian walking speed were found in this study. A mean total delay of 5.10 seconds was found in this study. Male and younger pedestrians experienced shorter delay compared to female and older pedestrians. The type of pedestrian facility and traffic signals during which pedestrians arrived at the kerb and crossed appeared to be other influential factors of pedestrian delay. With regard to gaze behaviour, an average number of head movements ranged from 2 to 5 at the kerb and from 3 to 5 while crossing. Conflicts with motorists peaked where crossing distances were longer and traffic volume was heavy. A red light violation ranging from 82 to 87 percent was observed in this study and on-street surveys indicated that beliefs and attitudes towards traffic control devices and traffic environment significantly explained pedestrians’ unsafe crossing behaviour. The calculated critical gap and critical lag ranged from 2.19 to 3.90 seconds and the effect of crossing distance on gap-acceptance emerged in this study. Possible interventions are finally suggested. / AFRIKAANSE OPSOMMING: Padongelukke is 'n wêreldwye probleem wat al die lande in die gesig staar. Ongeveer 1,2 miljoen mense sterf jaarliks as 'n gevolg van verkeersongelukke en 50 miljoen word beseer. Meer as 90 persent van padsterftes kom voor in die ontwikkelende wêreld met slegs 48 persent van die wêreld se geregistreerde voertuie. Bo en behalwe die probleem van padsterftes, het padongelukke gestremdheid en lang termyn beserings tot gevolg. Dit veroorsaak ook aansienlike ekonomiese verliese vir die slagoffers en hul gesinne en skade aan eiendomme en infrastruktuur. In Suid-Afrika is voetgangersterftes verantwoordelik vir sowat 40% van alle padongelukke. Gedragspatrone van beide voetgangers en motoriste by voetoorgange is die belangrikste bepalende faktore van voetganger-ongelukke. Hierdie studie ondersoek gedragspatrone van voetgangers by verskillende tipes kruisings in die dorp van Stellenbosch Suid-Afrika. ʼn Totale aantal van 17 voetoorgange is gekies vir die studie op die basis van hul geometriese en operasionele eienskappe. Video-gebaseerde waarnemings saam met op-straat onderhoude is gebruik om kruising-gedragspatrone, naamlik voetganger stapspoed, voetganger vertraging, kyk gedrag, voetganger-voertuig konflikte, voetganger nakoming van padverkeersreëls en gaping-aanvaarding gedrag te verstaan. Resultate van die studie het getoon dat manlike voetgangers vinniger loop as vroulike voetgangers. Die 15de persentiel kruising spoed vir alle voetgangers waargeneem binne kruisings was 1,13 m/s, terwyl die gemiddelde kruising spoed 1,48 m/s is. Demografiese veranderlikes beïnvloed voetgangers loop-spoed. Manlik en jonger voetgangers loop vinniger as vroulike en ouer voetgangers. Voetgangers loop-spoed word ook geraak deur die grootte van die groep, die dra van items, die tipe voetganger-fasiliteit en afleiding terwyl geloop word. Daar is egter geen gevolge van konflikte op voetgangers loop-spoed in hierdie studie gevind nie. 'n Gemiddelde totale vertraging van 5,10 sekondes is in hierdie studie gevind. Manlik en jonger voetgangers ervaar korter vertraging in vergelyking met die vroulike en ouer voetgangers. Die tipe voetgangerfasiliteit en verkeerseine was ander invloedryke faktore van voetganger vertraging. Vir waarneming van die verkeer is gevind dat die gemiddelde aantal kopbewegings gewissel het van 2 tot 5 teen die randsteen en van 3 tot 5, tydens die kruising. Konflikte met motoriste het ʼn hoogtepunt bereik waar kruising afstande langer en verkeersvolume hoër was. Rooi lig oortredings wat wissel van 82 tot 87 persent is in hierdie studie waargeneem en op-straat opnames het aangedui dat houdings teenoor verkeer-beheer toestelle en die verkeersomgewing die voetgangers se onveilige kruising-gedrag verduidelik. Die berekende kritiese gaping het gewissel van 2,19 tot 3,90 sekondes en die effek van die kruisinglengte op gaping-aanvaarding het in hierdie studie na vore gekom. Moontlike intervensies word voorgestel.