Simulating the Impact of Traffic Calming Strategies

This study assessed the impact of traffic calming measures to the speed, travel times and capacity of residential roadways. The study focused on two types of speed tables, speed humps and a raised crosswalk. A moving test vehicle equipped with GPS receivers that allowed calculation of speeds and determination of speed profiles at 1s intervals were used. Multi-regime model was used to provide the best fit using steady state equations; hence the corresponding speed-flow relationships were established for different calming scenarios. It was found that capacities of residential roadway segments due to presence of calming features ranged from 640 to 730 vph. However, the capacity varied with the spacing of the calming features in which spacing speed tables at 1050 ft apart caused a 23% reduction in capacity while 350-ft spacing reduced capacity by 32%. Analysis showed a linear decrease of capacity of approximately 20 vphpl, 37 vphpl and 34 vphpl when 17 ft wide speed tables were spaced at 350 ft, 700 ft, and 1050 ft apart respectively. For speed hump calming features, spacing humps at 350 ft reduced capacity by about 33% while a 700 ft spacing reduced capacity by 30%. The study concludes that speed tables are slightly better than speed humps in terms of preserving the roadway capacity. Also, traffic calming measures significantly reduce the speeds of vehicles, and it is best to keep spacing of 630 ft or less to achieve desirable crossing speeds of less or equal to 15 mph especially in a street with schools nearby. A microscopic simulation model was developed to replicate the driving behavior of traffic on urban road diets roads to analyze the influence of bus stops on traffic flow and safety. The impacts of safety were assessed using surrogate measures of safety (SSAM). The study found that presence of a bus stops for 10, 20 and 30 s dwell times have almost 9.5%, 12%, and 20% effect on traffic speed reductions when 300 veh/hr flow is considered. A comparison of reduction in speed of traffic on an 11 ft wide road lane of a road diet due to curbside stops and bus bays for a mean of 30s with a standard deviation of 5s dwell time case was conducted. Results showed that a bus stop bay with the stated bus dwell time causes an approximate 8% speed reduction to traffic at a flow level of about 1400 vph. Analysis of the trajectories from bust stop locations showed that at 0, 25, 50, 75, 100, 125, 150, and 175 feet from the intersection the number of conflicts is affected by the presence and location of a curbside stop on a segment with a road diet

17-11 Evaluation of Transit Priority Treatments in Tennessee

Many big cities are progressively implementing transit friendly corridors especially in urban areas where traffic may be increasing at an alarming rate. Over the years, Transit Signal Priority (TSP) has proven to be very effective in creating transit friendly corridors with its ability to improve transit vehicle travel time, serviceability and reliability. TSP as part of Transit Oriented Development (TOD) is associated with great benefits to community liveability including less environmental impacts, reduced traffic congestions, fewer vehicular accidents and shorter travel times among others.This research have therefore analysed the impact of TSP on bus travel times, late bus recovery at bus stop level, delay (on mainline and side street) and Level of Service (LOS) at intersection level on selected corridors and intersections in Nashville Tennessee; to solve the problem of transit vehicle delay as a result of high traffic congestion in Nashville metropolitan areas. This study also developed a flow-delay model to predict delay per vehicle for a lane group under interrupted flow conditions and compared some measure of effectiveness (MOE) before and after TSP. Unconditional green extension and red truncation active priority strategies were developed via Vehicle Actuated Programming (VAP) language which was tied to VISSIM signal controller to execute priority for transit vehicles approaching the traffic signal at 75m away from the stop line. The findings from this study indicated that TSP will recover bus lateness at bus stops 25.21% to 43.1% on the average, improve bus travel time by 5.1% to 10%, increase side street delay by 15.9%, and favour other vehicles using the priority approach by 5.8% and 11.6% in travel time and delay reduction respectively. Findings also indicated that TSP may not affect LOS under low to medium traffic condition but LOS may increase under high traffic condition

Sensitivity Analysis on Traffic Crash Prediction Models by Using STATA

Traffic accidents results from the interaction of different parameters which includes highway geometrics, traffic characteristics and human factors. Geometric variables include number of lanes, lane width, median width, shoulder width, roadway length, number of intersections, access density and shoulder width while traffic characteristics include AADT and speed. The effect of these parameters can be correlated by predictive models that predict crash rates at particular roadway section. STATA software commands it can be used to test the sensitivity of these variables on crash rate after modeling. In the current research sponsored by Florida Department of Transportation titled "Evaluation of Geometric and Operational Characteristics affecting the safety of Six-lane divided Roadways" we use these commands to determine the effect in crash rate as the result of change on these independent variables. We selected our model based on the user written command nbvargr which gives dispersion factor between Poisson and Negative Binomial. By using Vuong's value we were able to choose between Zero-Inflated and normal models. Through the command listcoef, percent we determine percent change in crash rate for unit and standard deviation increase in independent variables. By using the command mfx compute we were able to determine numerically the marginal effects or the elasticities between crash rate and the independent variables. These commands and others built in STATA reveal if the increase in size or dimension for roadway geometrics will result in higher crash rate or reduction.

15-09 Impact of Access Management Practices to Pedestrian Safety

This study focused on the impact of access management practices to the safety of pedestrians. Some of the access management practices considered to impact pedestrian safety included limiting direct access to and from major streets, locating signals, limiting the number of conflict points and separating conflict areas, removing turning vehicles from through traffic lanes, using nontraversable medians to manage left-turn movements and providing a supporting street and circulation system. The study evaluated through statistical modeling the correlation between access management practices to pedestrian crashes. Focused on the impacts of access management on pedestrian crashes, eight (8) major roadway corridors were selected and utilized for analysis. Utilizing Negative Binomial, the correlation between roadway features and pedestrian crashes were modeled. Four variables including AADT, access density, percentage of trucks and the presence of TWLT were found to be positively associated with the pedestrian crash frequency. Variables such as the presence of median, presence of crosswalk, presence of shoulders, presence of sidewalk and high speed limit had negative coefficients hence their increase or presence tends to decrease pedestrian crashes. It could therefore be concluded that though these variables had some influence on the pedestrian crashes, access density, crosswalk, sidewalk and speed limit were the most statistically significant variables that determined the frequency of the pedestrian crashes

16-11 Microsimulation of the Impact of Access Management Practices to Pedestrians

The study applied microsimulation to analyze the impact of access management (AM) to the operational performances of vehicles and pedestrians. A conceptual model was developed in VISSIM and VISWALK to examine the effect of access and signals density on different median types to the travel speed, travel time, delay and stopping. Access density, signal density, and presence of median were simulated in a scenario base analysis. The model scenarios shifted through changing both access density and signal density with no median, raised median and TWLT lane to provide interactions of arterial corridors in Nashville. The effect of access density on speed, delay and travel time was very vivid for the vehicles within the corridors showing speed decreasing with the increase in access density while delay increased and the number of stops increased. Additionally, as signal density increased, a decreasing pattern in corridor vehicle speed was observed. Pedestrian performances changes were less dramatic indicating that access density had a minimal effect on the pedestrian speed operations. The same trend was observed on signal density which affected pedestrian speed by a small decrease as signal density increased. The findings may provide useful understanding to state policy makers in implementing Access Management guidelines

14-07 Development of Decision Support Tools to Assess Pedestrian and Bicycle Safety: Focus on Population, Demographic and Socioeconomic Spectra

Despite the increase of these non-motorized trips, bicyclists and pedestrians remain vulnerable road users that are often over represented in traffic crashes. While the currently used methods that identify hazardous locations serve their purpose well, majority represent a reactive approach that seeks improvement after crashes happen. This research addressed these issues and proposed decision support tools to aid the implementation of bicycle and pedestrian safety strategies. This work developed an access based tool to predict the expected number of crashes at different neighborhood levels. This tool combines the traditional methods such as those provided in the Highway Safety manual to predict the expected number of bicycle and pedestrian crashes. First, a cluster analysis technique is proposed and developed a Geographic Information Systems (GIS) technique to facilitate the identification of high crash locations. Safety Performance Functions (SPFs) are developed in form of mathematical equations to relate the number of crashes to area socioeconomic and demographic characteristics. An integrated system consisting of access database and safety performance functions, and whose interface is designed to automatically compute the number of crashes given the input values is developed. Basing on crash value, the tool can be adopted as a framework to guide the appropriate allocation of safety improvement resources

La educación virtual en el desarrollo de la creatividad de los estudiantes de la Carrera de Psicopedagogía de la UNACH

In this research it was proposed the objective to determine the level of creativity of the students and the active teaching methodologies developed by the teachers of the fourth, fifth and sixth semesters of the Psychopedagogy career of National University of Chimborazo during virtual education. The teaching-learning methodologies have an impact on the creativity of the students, being beneficial or detrimental in its development, since there are methodologies that are based on a rigid pedagogical model and there are other models such as the traditional and behavioral one, which they are based on discipline and the teacher assumes the figure of authority. On the other hand, there are other models such as the constructivist, where the student, guided by the teacher, is responsible and actively builds his own learning process. The methodology had a quantitative approach, its design was non-experimental, because the variables were not deliberately manipulated. The type of research by the objectives was basic and by the location, it was field research. In addition, it had a descriptive scope. The techniques for data collection were the Questionnaire of questions on "Virtual Teaching Methodologies" validated by experts and the VALCREA Creativity Questionnaire (Assessment of Creativity, Del Caño, Elices & Palazuelo, 2003) cited by Cordero (2014). For the statistical analysis, it was carried out in programs such as Excel, and the conclusion was that the level of creativity of the fourth, fifth and sixth semester students of the Psychopedagogy Career of the National University of Chimborazo corresponds to the average level and the teaching methodology used by the teachers is collaborative learning, which allows training students with initiative, confidence, originality and flexible thinking which lies specifically in the cognitive.En el presente trabajo de investigación se propuso como objetivo determinar el nivel de creatividad de los estudiantes y las metodologías de enseñanza activas desarrolladas por los docentes de cuarto, quinto y sexto semestre de la carrera de Psicopedagogía de la UNACH durante la educación virtual. Las metodologías de enseñanza-aprendizaje tienen un impacto dentro de la creatividad de los estudiantes, siendo beneficioso o perjudicial en el desarrollo de la misma, pues, existen metodologías que se fundamentan en un modelo pedagógico rígido como lo puede ser el tradicional y conductista, los cuales se basan en la disciplina, y el docente asume la figura de autoridad; al contrario de otros modelos, como lo es el constructivista, en donde el estudiante es guiado por el docente, y es él mismo quien construye activamente su propio proceso de aprendizaje. La metodología tuvo un enfoque cuantitativo, su diseño fue no experimental, porque no se manipularon en forma deliberada las variables. El tipo de investigación por el nivel o alcance fue descriptiva y exploratoria; por los objetivos fue básica; por el lugar fue de campo y bibliográfica; por el tipo de inferencia fue deductivo-inductivo; y por el tiempo fue transversal. Dentro de la unidad de análisis, la población fue de 262 estudiantes y 14 docentes, mientras que la muestra fue de tipo no probabilística e intencional o por conveniencia y se trabajó con 101 estudiantes y 9 profesores. Las técnicas para la recolección de datos fue el Cuestionario de preguntas sobre “Metodologías de enseñanza virtuales” validado por expertos y el Cuestionario de Creatividad VALCREA (Valoración de la Creatividad, Del Caño, Elices & Palazuelo, 2003) citado por Cordero (2014). Para el análisis estadístico se realizó en programas como Excel, y se llegó a la conclusión; que el nivel de creatividad de los estudiantes de cuarto, quinto y sexto semestre de la carrera de Psicopedagogía de la Universidad Nacional de Chimborazo corresponde al nivel medio y la metodología de enseñanza utilizada por los docentes es el aprendizaje colaborativo, el cual permite formar estudiantes con iniciativa, confianza, originalidad y de pensamiento flexible radica específicamente en la cognoscitivista.UNACH, Ecuado

The role of rap performance in reinforcing or challenging participants' perceptions of 'race' in post-apartheid South Africa, Durban.

Thesis (M.Mus.)-University of KwaZulu-Natal, Durban, 2008.This ethnographic study concerns itself with the role that local rap performance plays in either reinforcing or challenging perceptions of 'race' amongst the participants of hip-hop culture in Durban, South Africa, and what this implies for the prospects of reconciliation. Using Cohen's (1989) theory of community and Grossberg's (1996) theory of affective alliances, I explore the ways in which music may create and maintain differences and commonalities between groups of people. It is my hypothesis that genre conventions and connotations, and the discourses that circulate about rap music (for example, rap music as a form of expression particular to the 'black Atlantic' diaspora and conditioned by a racially segregated society [Rose 1994]), allow hip-hop to either reinforce or challenge participants' perceptions of 'race'. I examine how musical and lyrical utterances thrust into a semantic historical and socio-political context limit how rap performance can mean and how, as a dialogic speech genre, rap can uphold, subvert or negotiate its genre associations, including, through the use of double-voiced discourse, dominant ideas concerning 'race' and cultural identity. Acknowledging the idiom as of a form of black cultural expression (Rose 1994), interviewees mention narratives of hip-hop's historical origins, rap artists' use of Five Percenter and Black Nationalist ideologies, and poverty, as factors that either reinforce or challenge notions of 'race'. The simultaneous transgression of and/or adherence to, racialized space and spatialized 'race' (Forman 2002) by different 'races', as well as the presence or absence of multilingualism, are viewed as indicators of the level of commitment to the notion of a democratic place for all 'race' and language groups in post-apartheid South Africa. It is the aim of this thesis to add to the body of knowledge concerning the nature of our post-apartheid identities, what influences them and in what way. And in a broader context, to explore the role of music in societies in transition and the role it might play in facilitating an ability to 'imagine culture beyond the colour line' (Gilroy 2000)

Caracterización de la diversidad de artrópodos en parcelas con especies ocotea quixos y myroxylon balsamun en el centro de investigación, postgrados y conservación amazónica, Universidad Estatal Amazónica, periodo 2015-2016

The research has had as an aim the characterization of the diversity de arthropods at the Center of Investigation, Postgraduates and Amazonic Preservation, (CIPCA) where it was determined two parcels with three silvicultural treatments and it was establishing ten pitfall traps in each treatment. The successive samplings were done in order to maintain the traps in the same points during the entire trial. The traps attachment of fall had performed through the aggression of a soapy mixture of four liters, four grams of salt for each parcel, it is covering the 180 traps; 80 ml in each trap, the collection was done through vial bottles in alcohol to the 70% with its own labeling for its later identification.El presente estudio tuvo como objetivo la caracterización de la diversidad de artrópodos en el Centro de Investigación Postgrados y Conservación Amazónica (CIPCA). En donde se determinó dos parcelas con tres tratamientos silvícolas y se establecieron 10 trampas de caída (pitfall) en cada tratamiento. Los muestreos sucesivos se realizaron manteniendo las trampas en los mismos puntos durante todo el ensayo...