M.Com. (IT Management) / Vehicle traffic congestion on Gauteng’s metropolitan and national roads in South Africa remains a challenge, especially during peak hours and also when incidents occur. They hamper the flow of vehicle traffic. Traffic congestion has negative consequences for business and for commuters’ quality of life. The goal of this research project is to identify variables that influence the flow of traffic and to design a vehicle traffic prediction model which will predict the traffic flow pattern in advance, given a set of predictor variables that will enable motorists to make appropriate travel decisions ahead of time. The traffic flow was categorised into three classes, namely traffic jam, free flowing and flowing congestion. In this study, the artificial intelligence algorithms that include Bayesian Networks, K-Nearest-Neighbour, Multi-layer Perceptron (MLP) and C4.5 Decision Tree were used individually for predicting the vehicle traffic flow. The results obtained from these algorithms were compared using the predictive performance and prediction costs. The best predictive model is one that has lower cost and good performance. The results show that the MLP was the best performing algorithm in terms of predictive performance and low prediction costs. In order to predict a novel instance, a feed forward Multi-layer Perceptron network was built using Matlab and was used to predict the unseen vehicle traffic instance, also called a novel instance. The (MLP) model accurately predicts vehicle traffic flow on a single novel instance with a prediction performance of 80% (16 out of 20) on novel instances.

Roadway grades have a diverse effect on vehicle speeds, depending on vehicle and roadway characteristics. For example, passenger cars can generally negotiate grades of 5 percent or less without considerable reductions in vehicle speeds, while heavy-duty trucks are affected significantly by grades because of their inferior operating capability. Consequently, due to the potential significant speed differential between automobiles and heavy-duty trucks, these trucks can have a significant impact on the quality of flow, throughput, and safety of a traffic stream. Truck climbing lanes are typically constructed in an attempt to lessen this negative impact. Currently, the American Association of State Highway and Transportation Officials (AASHTO) and Highway Capacity Manual (HCM) represent the state-of-art and state-of-practice procedures for the design of truck climbing lanes. These procedures only consider the tangent vertical profile grades in the design of climbing lanes and do not capture the impact of vertical curvature on truck performance. The dissertation describes the TruckSIM framework for modeling vehicle motion along roadway sections by considering both the longitudinal and lateral forces acting on a vehicle. In doing so, the tool reflects the impact of horizontal and vertical alignment on a vehicle's longitudinal motion. The model is capable of reading Global Positioning System (GPS) (longitude, latitude, and altitude), roadway, and vehicle data. The dissertation demonstrates the validity of the software modeling procedures against field data and the HCM procedures. It is anticipated that by automating the design procedures and considering different vehicle and roadway characteristics on truck motion, the TruckSIM software will be of considerable assistance to traffic engineers in the design of roadways. The Global Positioning System (GPS) was originally built by the U.S. Department of Defense to provide the military with a super-precise form of worldwide positioning. With time, GPS units were introduced into the civilian domain and provided transportation professionals with an opportunity to capitalize on this unique instrumentation. With this GPS capability, this research investigates the feasibility of using inexpensive WAAS-capable units to estimate roadway vertical and horizontal profiles. The profiles that are generated by these inexpensive units (less than $500) are compared to the profiles generated by expensive carrier-phase DGPS units ($30,000 per unit including the base station). The results of this study demonstrate that the use of data smoothing and stacking techniques with the WAAS data provides grade estimates that are accurate within 10% of those generated by the carrier-phase DGPS units and thus offer a cost effective tool for providing input data to the TruckSIM software. Using the TruckSIM software, this research effort investigates truck performance reflective of various truck and road characteristics. These characteristics include vehicle engine power, weight-to-power ratio, pavement type, pavement condition, aerodynamic aid features, engine efficiency, tire type, and percentage mass on tractive axle. The study demonstrates that the vehicle weight-to-power ratio, vehicle engine power, pavement surface condition, tire type, aerodynamic aids, and engine efficiency are critical factors in the design of truck climbing lanes. / Ph. D.

Passenger car equivalents (PCEs) are used in highway capacity analysis to convert a mixed vehicle flow into an equivalent passenger car flow. This calculation is relevant to capacity and level of service determination, lane requirements, and determining the effect of traffic on highway operations. The most recent Highway Capacity Manual 2000 reports PCEs for basic freeway segments according to percent and length of grade and proportion of heavy vehicles. Heavy vehicles are considered to be either of two categories: trucks and buses or RVs. For trucks and buses, PCEs are reported for a typical truck with a weight to power ratio between 76.1 and 90.4 kg/kW (125 and 150 lb/hp). The weight to power ratio is an indicator of vehicle performance. Recent development of vehicle dynamics models make it possible to define PCEs for trucks with a wider variety of weight to power ratios. PCEs were calculated from the relative impact of trucks on traffic density using the simulation model INTEGRATION. The scope of this research was to evaluate PCEs for basic freeway segments for trucks with a broader range of weight to power ratios. Such results should make freeway capacity analysis more accurate for mixed vehicle flow with a non-typical truck population. In addition, the effect of high proportion of trucks, pavement type and condition, truck aerodynamic treatment, number of freeway lanes, truck speed limit, and level of congestion was considered. The calculation of PCEs for multiple truck weight to power ratio populations was not found to be different from single truck weight to power ratio populations. The PCE values were tabulated in a compatible format to that used in the Highway Capacity Manual 2000. / Master of Science

Increasing interest in driving for pleasure has put a burden of crowding and over-use on many of our nation's scenic highways. The carrying capacity concept says that there is an acceptable level of use or change for a resource beyond which that resource will be significantly degraded. This thesis examines the applicability of this concept to the problems of crowding and over-use of scenic roadways. This study developed as an attempt to bridge the gap between recently developed carrying capacity models in recreation resource management and planning and the specific problems of scenic roadways. While carrying capacity theory and practice have produced good models, the unusual characteristics of scenic roadways challenge the direct application of these models. A questionnaire was distributed to scenic roadway designers, planners, and managers; roadway researchers; carrying capacity researchers; and recreation resource managers nationwide. Respondents answered questions about the value of carrying capacity for managing scenic roadways, about perceived problems in implementing a carrying capacity program for scenic roadways, about the appropriate scope of a carrying capacity management tool for scenic roadways, and about needs for future research to support development of a carrying capacity model for scenic roadways. Responses to the questionnaire indicate strong support for developing a management tool for scenic roadways based on the carrying capacity concept. Responses support a broad-based approach to addressing the carrying capacity of scenic roadways, looking at both the roadway and lands adjacent to the roadway in attempts to determine carrying capacity. / Master of Landscape Architecture

Cheung, Kin Tai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 34-35). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Contents --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature Review --- p.4 / Chapter 3 --- Data Description --- p.7 / Chapter 4 --- Ordinary Least-Squares and Fixed-Effect Estimations --- p.10 / Chapter 4.1 --- OLS Estimation --- p.10 / Chapter 4.2 --- Fixed-Effect Estimation --- p.13 / Chapter 5 --- Cross-sectional and Fixed-Effect IV Estimations --- p.16 / Chapter 5.1 --- Cross-sectional IV Model --- p.16 / Chapter 5.2 --- Fixed-Effect IV Model --- p.23 / Chapter 6 --- Conclusion --- p.29 / Appendix --- p.30 / Estimation Results for Honshu Island --- p.30 / Ordinary-Least Squares Results in 150 observations regression --- p.33 / References --- p.34

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Although extensive research has been conducted on urban freeway capacity estimation methods, minimal research has been carried out for rural highway sections, especially sections within work zones. This study filled that void for rural highways in Kansas. This study estimated capacity of rural highway work zones in Kansas. Six work zone locations were selected. An average of six days’ worth of field data was collected, from mid-October 2013 to late November 2013, at each of these work zone sites. Two capacity estimation methods were utilized, including the Maximum Observed 15-minute Flow Rate Method and the Platooning Method divided into 15-minute intervals. The Maximum Observed 15-minute Flow Rate Method provided an average capacity of 1469 passenger cars per hour per lane (pcphpl) with a standard deviation of 141 pcphpl, while the Platooning Method provided a maximum average capacity of 1195 pcphpl and a standard deviation of 28 pcphpl. Based on observed data and analysis carried out in this study, the recommended capacity to be used is 1500 pcphpl when designing work zones for rural highways in Kansas. This research provides the proposed standard value of rural highway work zone capacities so engineers and city planners can effectively mitigate congestion that would have otherwise occurred due to impeding construction/maintenance.

Tese de mestrado integrado. Engenharia Civil. Área de Especialização de Vias de Comunicação. Faculdade de Engenharia. Universidade do Porto. 2012

This thesis fills a missing piece in research on multimodal performance measures for traffic on streets and highways. The Highway Capacity Manual (HCM) published by the Transportation Research Board (TRB) provides Level of Service (LOS) methodologies which enable engineers and planners to evaluate the overall performance of roadways and highways based on the physical characteristics of facilities. This allows for the evaluation of those facilities and offers a means for recognizing issues and planning, designing, implementing, and ultimately assessing improvements. Originally, level of service was developed for automotive traffic only, but with recent developments as part of the complete streets movement, the performance of infrastructure for alternative transportation modes have also started being assessed in this fashion. There are methodologies in HCM 2010 for bicycle traffic at signalized intersections, all-way stop-controlled intersections, roadway and highway segments, but as of yet, no bicycle level of service methodology exists for two-way stop-controlled intersections. This work attempts to fill this gap. The methodology utilized for this report includes video collection of sample two-way stop-controlled intersections throughout California, collection of survey responses from viewers of video, and linear regression of collected survey responses with physical attributes of each sample intersection as the explanatory variables. Data was analyzed from both combined and individual street movements to determine the final equation set. The final methodology involves two separate procedures for major and minor streets at TWSC intersections. Final factors deemed significant in bicycle level of service analysis include sight distances, speed limits, presence of bus stops, presence and type of bicycle infrastructure, street widths and types of lanes present, pavement quality, and traffic flows.

Automated Electric Transportation (AET) is a concept of an emerging cooperative transportation system that combines recent advances in vehicle automation and electric power transfer. It is a network of vehicles that control themselves as they traverse from an origin to a destination while being electrically powered in motion – all without the use of connected wires. AET's realization may provide unparalleled returns in the form of dramatic reductions in traffic-related air pollution, our nation’s dependence on foreign oil, traffic congestion, and roadway inefficiency. More importantly, it may also significantly improve transportation safety by dramatically reducing the number of transportation-related deaths and injuries each year as it directly addresses major current issues such as human error and adverse environmental conditions related to vehicle emissions. In this thesis, a logical strategy in transitioning from today’s current transportation system to a future automated and electric transportation system is identified. However, the chief purpose of this research is to evaluate the operational parameters where AET will be feasible from a transportation operations perspective. This evaluation was accomplished by performing lane capacity analyses for the mainline, as well as focusing on the merging logic employed at freeway interchange locations. In the past, merging operations have been known to degrade traffic flow due to the interruptions that merging vehicles introduce to the system. However, by analyzing gaps in the mainline traffic flow and coordinating vehicle movements through the use of the logic described in this thesis, mainline traffic operations can remain uninterrupted while still allowing acceptable volumes of merging vehicles to enter the freeway. A "release-to-gap" merging algorithm was developed and utilized in order to maximize the automated flow of traffic at or directly downstream of a freeway merge point by maximizing ramp flows without causing delay to mainline vehicles. Through these tasks, it is the hope of this research to aid in identifying the requirements and impending impacts of the implementation of this potentially life-altering technology.

Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 143-156). Also available in electronic format on the Internet.