Traffic Engineering

Traffic congestion has become a great challenge and a large burden on both the governments and the citizens in vastly populated cities. The main problem, originally initiated by several factors, continues to threaten the stability of modern cities and the livelihood of its habitants. Hence, improving the control strategies that govern the traffic operations is a powerful solution that can solve the congestion problem. These improvements can be achieved by enhancing the traffic control performance through adjusting the traffic signal timings. This paper focuses on finding various solutions for the addressed problem through the optimization using simulation of traffic signal timings under oversaturated conditions. The system under study is an actual road network in Alexandria, Egypt; where, numerous data have been collected in different time intervals. A series of computer simulation models to represent the actual system as well as proposed solutions have been developed using the Exte...

Traffic bottlenecks are a common feature of
urban transportation, particularly at signalized junctions.
The primary cause is inconsistent roadside parking control
(on-street parking), which impacts traffic saturation at
signalized junctions. This study attempts to develop an
effective model for parked cars at a specific distance from
the stop line in the face of congested traffic to establish the
appropriate parking ban distance at the junction. This study
developed a simulation to position a vehicle at a specific
distance, observe traffic movement at the junction, and
assess parking boundaries to create an appropriate distance
model. All cycles witnessed during traffic saturation
circumstances are videotaped. Data collection at the
entrance line occurred when there was no parking and at
distances of 5, 10, 20, and 30 meters from the stop line; this
was collected during one peak hour. The study's findings
provide a linear mathematical model for the association
between traffic saturation and parking distance. The
presence of parking substantially impacts variations in
saturation current value at a distance of 35 meters from the
stop line. Therefore, the efficacy of enforcing the parking
prohibition extends from the stop line to 35 meters,
allowing parking at distances more significant than this
value. We hope these and other studies can serve as a
foundation for creating on-street parking design
suggestions.

The network traffic classification is essential in identifying and categorizing the network traffic data packets in the network transmission. The network traffic transmission is effectively managed and prioritized using Quality of Service (QoS). The Differential Services Code Point within the Differentiated Service (DiffServ) field is primarily used inside the Layer 3 encapsulated network IP packets. Since the user generated data is growing rapidly with variety in data such as, streaming, VoIP, online gaming etc. There is a need to have effective prioritization and classification of IP packets for routers to enable the forwarding of such packets including packets having critical data efficiently and with a lower drop rate. This study develops and analyze using neural network-based models for effective classification of data packets using the DSCP header field. The data was gathered using real-time packet capturing tools which were then processed and moved with model development using different deep learning algorithms such as, LSTM, MLP, RNN and Autoencoders. Most of the algorithms got promising results and classify packets based on DSCP accurately. This study will help to advance network packet classification within the network transmission by network administrators to monitor network more efficiently and to avoid malicious activities within the network environment.

The advancement in wireless networking and wireless device technology are paving the way for bringing the vision of ubiquitous communication to reality. This vision will be enabled by the interworking of existing wireless multihop wireless networks. However, the diversity in the design and operation of these wireless networks may not enable users to enjoy continuous network service as they traverse between networks. This paper presents a framework which ensures continuous service and sustains an acceptable service level quality for network users transiting between multiple multihop wireless networks. The focus is on the scenario where a user utilizes multiple hops to access any of the multiple networks. We classify the components of the framework into link discovery, resource optimization and routing

This research utilizes historical data on traffic volume, wind speed and direction, air humidity, air temperature, air pressure, solar radiation, cloud cover and surface height. Air dispersion analysis was carried out using AERMOD software. The highest emissions obtained were 67,121 μg/m 3 for CO and 9,570 μg/m 3 for NO x under existing conditions and after implementing traffic management measures, the highest emissions were reduced to 45,737 μg/m 3 for CO and 7,217 μg/m 3 for NO x. These results conclude that traffic management can reduce air pollution. Air dispersion is not only influenced by vehicle volume but also meteorological factors. This can be seen in the dispersion results. Where, the conditions before and after traffic management showed differences in terms of the distribution of air dispersion

The energy consumption of network devices, and, as a consequence, of communication networks, is generally independent from their level of utilization, which results in a waste of energy when the network is lightly loaded. Ideally the consumption of a network should be proportional to the amount of traffic it conveys. The most straightforward way to enforce such a proportionality between the network energy consumption and its utilization level, is to dynamically adapt the status of network devices to the load, forcing a subset of them to enter a sleep state during the low activity periods. We present in this paper an algorithm to dynamically put links into a sleep state, based on a cooperative-game approach, named "L-Game". Our approach decides which links can be switched off based on a measure of the criticality of each link expressed as its Shapley value. This measure combines topological aspects and traffic conditions. Simulation results on real network scenarios show that our solution achieves a better trade off between energy saving and Traffic Engineering than other legacy approaches.

Highway-rail grade crossing (HRGC) crashes in non-divided two-way traffic scenarios have caused numerous fatalities and injuries over the years. Although crucial to the safety of multimodal transportation systems, these crossings have received little attention and previous studies did not fully account for the unobserved heterogeneity and its potential interactive effects. To bridge these gaps, the HRGC crashes occurring between 2019 and 2020 in the United States were collected from the Federal Railroad Administration's Office of Safety Analysis System. A random parameters logit model with heterogeneity in means was developed to investigate the impact of multiple factors associated with crossings, crashes, drivers, vehicles, and the environment. The present study indicates that did not stop behavior generates the random parameter with heterogeneity in means that is influenced by the dark and land with commercial power indicators. Furthermore, the findings show that factors such as estimated vehicle speed > 25 MPH, train speed > 45 MPH, going around the gate, old driver, female driver, motorcycle, and the driver was in vehicle indicators would increase the likelihood of more severe injury outcomes in HRGC crashes. Notably, the adverse crossing surface and truck indicators demonstrate unexpected marginal effects by reducing the likelihood of severe injury outcomes at non-divided two-way traffic HRGCs. This study emphasizes the importance of considering unobserved heterogeneity in the context of HRGC crashes. The findings can serve as a foundation for developing targeted interventions aimed at enhancing road and railway safety.

Optical Burst Switching (OBS) is a promising switching paradigm to efficiently support Internet Protocol (IP) packets over optical networks, under current and foreseeable limitations of optical technology. The prospects of OBS networks would greatly benefit, in terms of cost and ease of implementation, from limiting the wavelength conversion capabilities at the network nodes. This paper presents a framework for contention minimization/resolution combining traffic engineering in the wavelength domain to minimize contention in advance and optical buffering at the core nodes to resolve contention. Simulation results show that with the proposed contention minimization/resolution framework the large number of expensive all-optical wavelength converters used at the core nodes of an OBS network can be replaced by a moderate number of shared optical delay lines without compromising network performance.

SDN Angkasa V Lanud Sulaiman yang terletak pada tepi ruas Jalan Terusan Kopo yangmerupakan akses menuju kawasan industri. Dengan begitu arus lalulintas di ruas jalan tersebutmeningkat yang menimbulkan kebisingan pada lokasi pendidikan tersebut. Studi ini bertujuanuntuk menghitung volume lalulintas, kecepatan rata – rata lalulintas, tingkat kebisingan lalulintasdan membuat model kebisingan lalulintas. Metode yang dilakukan dalam penelitian adalah dengansurvei langsung di lapangan dan untuk menganalisis pemodelan kebisingan lalulintasmenggunakan analisis regresi linier berganda dengan bantuan software SPSS (statistical packageof the social sciences) versi 17.0. Dari hasil studi diperoleh bahwa pada Jalan Terusan Kopovolume lalulintas yang terjadi pagi hari sebesar 3322,35 smp/jam, pada siang hari sebesar 2596,7smp/jam dan pada sore hari sebesar 2864,9 smp/jam. Untuk kecepatan rata-rata lalulintas yangterjadi adalah 36,00-51,50 km/jam untuk sepeda motor (MC), 31,00-45,00 km/jam untukke...

Internet has become a worldwide data network that is used for mission critical applications. The global internet implies several important challenges. The first challenge is the size of the internet which grows enormously in a rapid rate. Hence the traffic on the internet work also increases day to day. Traffic engineering is performed by means of a set of techniques that can be used to better control the flow of packets inside an IP network. This paper proposes a throughput optimisation of both inter-and intra-autonomous systems traffic engineering. Also the optimisation concepts are compared by implementing in various strategies such as sequential, nested and integrated techniques.

Traffic engineering, as its name, is the art of manipulating traffic around so that traffic from congested links is moved onto the unused capacity on the other links. So, providing traffic engineering support in multi-hop wireless network has become increasingly important due to the low bandwidth nature of wireless channels. In this work, we propose a novel approach to control the traffic to avoid congestion by decoupling forwarding process from the routing process. The proposal is interested in provisioning quality of service guarantees for planned Wireless Mesh Networks which are being used widely as a broadband wireless access network.

In recent years, many departments of transportation in the US have invested additional resources to enhance pedestrian safety. However, there is still a need to effectively and systematically address the pedestrian experience in low-income areas. A Governing analysis of pedestrian crashes found that pedestrians are fatally injured at disproportionately higher rates in the nation's poorer neighborhoods, and in metro areas, low-income tracts record pedestrian fatality rates approximately twice those of more affluent neighborhoods. Low-income areas often are sectioned by high volume/high speed arterials, which compounds the problem. This research developed a demographics-based methodology that identifies the quantitative relationships between dependent variables such as pedestrian crashes and severe injury crashes and independent variables including demographic and social factors, road environmental factors, neighborhood land use attributes, and individual characteristics in low-income areas. For demographic and social factors, major influential variables include proportions of older adults, commuters using public transit or biking, people with a low education level, and zero-car ownership. For road environmental factors, major influential variables include number of traffic signals per census block group, number of bus stops per mile, and proportion of higher-speed roads in a census block group. For neighborhood land use attributes, major influential variables include densities of discount stores, convenience stores, and fast-food restaurants. Additionally, dark-not lighted condition is the most influential variable for severe injury in pedestrian crashes. The number of impaired pedestrians and aggressive drivers also greatly increases the probability of severe injury. Based on the demographics-based analysis and results, this study makes specific recommendations for both engineering countermeasures and pedestrian safety education/outreach plans that resonate with a given area's demographics to effectively improve pedestrian safety in low-income areas. 17. Key Word Pedestrian safety; low-income area; demographic analysis; crash frequency, injury severity; countermeasures; land use types 18. Distribution Statement 19. Security Classif. (of this report) 20. Security Classif.

This study examined the feasibility of just one approach to coordinating transportation and land use planning. The lack of such coordination in the United States has been the subject of much criticism. In rural areas, the locality usually controls land development decisions whereas the state generally controls transportation decisions. In Virginia, Botetourt County and the Virginia Department of Transportation (VDOT) initiated a pilot planning process to coordinate transportation and land use planning. In that process, VDOT personnel served as staff for the county, which was the client. The immediate goal of this effort was a scenarios analysis. Botetourt specified potential zoning scenarios for consideration, and VDOT estimated the likely impacts of each scenario on the immediate transportation network. Botetourt benefited from this relationship by having access to engineering staff who can provide a quantitative analysis of delay at key intersections, and VDOT benefited by helping to ensure that Botetourt had the opportunity to consider the transportation impacts in its zoning decisions. To support this scenarios development, three additional deliverables were developed: a data element protocol, an action plan, and a template for replicating this process with other Virginia counties. Seven steps comprise this template: (1) define a problem statement quickly, imperfectly, and iteratively; (2) use quick updates to resolve shortcomings; (3) maintain momentum; (4) keep everyone updated equally; (5) recognize that the county is the client; (6) dedicate staff; and (7) end the process with a tangible deliverable. Details of how these steps were accomplished are provided to facilitate the transfer of these lessons to other counties and VDOT.

Virginia's 2003 General Assembly directed the Secretary of Transportation to(1) assess best practices used by other states to coordinate transportation and land use planning;(2) review current state efforts to provide technical assistance to local governments in the ...

Increase in traffic flow in a region reflects the development of transport infrastructure. Transport infrastructure development arises due to new investment in the region as it is a significant factor for assessing the social and economic viability of any highway project. Impact of economics on traffic is difficult to analyze traffic flow projection. To comprehend the objective, economic attributes such as investment and employment generated in the region are considered for the traffic growth and also, IRC-108 specified econometric model was developed using net state domestic product (NSDP). A regression analysis was developed for predicting traffic with economic attributes stated above and found to be linear. Precision of model was gauged, based on mean absolute percentage error (MAPE) rather only considering the coefficient of determination.

Transportation occupies a prominent place in modern life and its impact is spread in all domains of life. Transport planning is a discipline to study problems rising while planning transport facilities at urban, regional or national level and to prepare efficient basis for providing such facilities. Aim of transport planning at regional level is provision of connectivity and circuity with other regions as well as for expansion of existing facility for future needs. The key success for transportation planning is the accurate forecasting of vehicular movement. The accuracy of traffic forecasting is a point of substantial importance to the effective sharing of rationed resources. With this purpose, study was conducted to develop traffic flow prediction model by aggregate approach and disaggregate approach for industrial corridor (i.e., state highway 158) passing through Savali taluka in Vadodara, India. To accomplish this goal, traffic volume of past 10 years collected in two terms, pre-monsoon and port-monsoon from state Public Work Department. For aggregate approach, economic parameters such as investment and employment generated in the region while in disaggregate approach time series analysis using auto regressive technique were utilized for traffic prediction. The relation developed between existing traffic and investment as well as with employment was found to be linear. Precision of model was gauged, based on mean absolute percentage error (MAPE) rather only considering the coefficient of determination. Finally, the study highlights the effects of economic development on transport infrastructure and its future need in the region. The results and approaches adopted here can be useful for planners in implementation and development of a transportation system.

Transportation occupies a prominent place in modern life and its impact is spread in all domains of life. Transport planning is a discipline to study problems rising while planning transport facilities at urban, regional or national level and to prepare efficient basis for providing such facilities. Aim of transport planning at regional level is provision of connectivity and circuity with other regions as well as for expansion of existing facility for future needs. The key success for transportation planning is the accurate forecasting of vehicular movement. The accuracy of traffic forecasting is a point of substantial importance to the effective sharing of rationed resources. With this purpose, study was conducted to develop traffic flow prediction model by aggregate approach and disaggregate approach for industrial corridor (i.e., state highway 158) passing through Savali taluka in Vadodara, India. To accomplish this goal, traffic volume of past 10 years collected in two terms, pre-monsoon and port-monsoon from state Public Work Department. For aggregate approach, economic parameters such as investment and employment generated in the region while in disaggregate approach time series analysis using auto regressive technique were utilized for traffic prediction. The relation developed between existing traffic and investment as well as with employment was found to be linear. Precision of model was gauged, based on mean absolute percentage error (MAPE) rather only considering the coefficient of determination. Finally, the study highlights the effects of economic development on transport infrastructure and its future need in the region. The results and approaches adopted here can be useful for planners in implementation and development of a transportation system.

Inadequate road conditions are a major challenge to transportation safety, contributing to a significant number of accidents, injuries, and fatalities annually. These unsafe conditions not only jeopardize individual drivers but also strain public safety systems and healthcare resources. Despite growing research into road safety factors, the specific effects of poor road infrastructure-such as deteriorated road surfaces, insufficient signage, and inadequate maintenance-remain insufficiently studied. Filling this research gap is critical for creating effective strategies to reduce accidents and improve safety on the roads.

The objective of this study is to find the relationship between saturation flow and vehicle speed on the study location. Data of saturation flow and speed of vehicle were collected with a survey of traffic on the location of study.. Saturation flow was determined by time slice method of 5 seconds. Data of vehicle speed was calculated as a distance from stopline to the exitlane per time taken by each vehicle leaving from stopline to the exit lane. The result of this study indicate that the relationship between saturation flow and vehicle speed leaving from stopline to the exitlane followed the ekspontial model,

We demonstrate a converged OpenFlow enabled packet-circuit network, where circuit flow properties (guarantee d bandwidth, low latency, low jitter, bandwidth-on-demand, fast recovery) provide differential treatment to dynamically aggregated packet flows for voice, video and web traffic.

Motorcycle transportation commonly known as boda boda, is very useful in rural areas of Kenya due to poor infrastructure. Statistics from the Kenya police indicate that this mode of transport accounts for most road accidents in Kakamega County. This leads to injuries, maiming, or death. The research was conducted to evaluate the impact of training levels undertaken by boda boda operators on road safety, accidents, and their awareness levels on safety measures. Four hundred and eighty questionnaires were randomly administered to boda boda operators, health facilities and law enforcement officers. The variables included age, education level, marital status, training level and awareness, ownership, time of operations and number of passengers ferried. It was observed that 64% of boda boda operators had no valid licenses. About 51% of the operators were trained through apprenticeship, 33% through driving school and 16% self-training. An average of 61% did not have any road safety trainin...

Jawa Timur merupakan provinsi yang memiliki populasi penduduk sekitar 37,47 juta jiwa.Hal ini berimbas kepada meningkatnya kebutuhan untuk melakukan perjalanan dari tempat awal menuju ke tempat tujuan. Jalan merupakan prasarana yang mendukung hal tersebut. Menurut data Dinas PU Bina Marga, tahun 2012, rasio panjang jalan terhadap jumlah kendaraan di Jawa Timur tercatat 3,29 km untuk setiap 1000 kendaraan bermotor. Hal ini disebabkan pertumbuhan jumlah kendaraan bermotor yang lebih cepat dibandingkan dengan pertumbuhan panjang jalan yang ada.. Jalan tol merupakan salah satu jenis jalan yang dipergunakan untuk mempercepat laju perpindahan tersebut. Kualitas yang baik dari jalan tol memberikan jaminan terhadap kecepatan distribusi barang dan jasa. Tetapi kenyataannya, jalan tol tidak dapat menjamin penuh akan hal tersebut karena salah satu faktor tersebut adalah waktu dan kualitas pelayanan di pintu tol. Banyak pintu tol yang tidak mencukupi dari segi kinerja maupun pelayanan. Padahal, pintu tol sangat penting untuk diperhatikan, karena akan mempengaruhi jumlah kendaraan yang akan masuk ke gerbang tol yang lain. Selain itu, kualitas dari pelayanan yang diberikan akan memberikan dampak yang signifikan terhadap jumlah laju kendaraan yang dapat dilayani. Dalam tugas akhir ini membahas antrian yang terjadi pada gerbang tol yang ada. Antrian adalah suatu garis tunggu dari

Until now the unsafety or accident potential of road locations has been assessed usually solely from their accident history. But this approach has been criticised as fundamentally misleading and inaccurate by many authors. Safety evaluation, particularly in Ghana, is also still restricted to isolated blackspot analysis. Because of its site-specific nature, this represents a less efficient use of scarce resources whilst there is generally a dearth of knowledge regarding the accident potential associated with various road locations and features. Based on a case-study of unsignalised urban junctions in Ghana, this dissertation presents the Empirical Bayesian procedure for the estimation of site-specific accident potential as a superior alternative that automatically addresses the shortcomings inherent in the sole use of recorded accident counts. The refined estimate is produced from a uniquely weighted combination of the recorded accident counts of the particular site and the expected accidents for sites with similar characteristics as the one under study. A unique feature of this study is the demonstration of the framework for integrating comprehensive accident model predictions with the Empirical Bayesian procedure, to improve further upon the quality of the estimates and extend the applicability of the procedure to relatively smaller reference populations. Despite the acknowledged advantages of this approach, little work has been done in this direction, largely due to the absence of appropriate prediction models, particularly for traffic conditions in developing countries. Thus, a key part of this study has been the development of accident prediction models for unsignalised Tand X-junctions. The models were of two types, namely, the coarse or flow-based, which included only traffic exposure functions as the explanatory variable, and the full or comprehensive models, containing both exposure functions and other significant road and traffic variables. Separate models have been developed to predict the three-year frequency of total accidents, injury accidents and five other types of accidents defined by the primary collision types involved. The unique ability of the Bayesian analysis to treat

IS-IS (Intermediate System to Intermediate System) routing protocol uses a simple metric system, which in most cases has to be adapted to specific conditions. This paper presents requirements and a proposed solution for RoEduNet2 IS-IS routing engineering, in order to achieve a good traffic distribution in the network structure. A formula to calculate the IS-IS metric is presented, considering several

This study focuses on real-time incident detection on coastal urban roads and on traffic diversion benefits. The main objective is to detect real-time incidents on a busy coastal road in a city center, leading to the port. Following incident detection, road users are to be informed through Variable Message Sign (VMS). Port users are expected to benefit from incident detection and coastal road users’ diversion since they can reach port on time. Coastal road users will be diverted to alternative routes to reach their destinations avoiding port traffic delays. A real time incident detection algorithm was parameterized for urban roads and Intelligent Transportation Systems (ITS) data were analyzed. We simulated congestion and accident conditions on a coastal road segment in Patras and traffic diversion rates, estimating diversion benefits based on site data and performance indices.

This study examines the behaviour of vehicles at a four way stop in close proximity to the University, along one of the principal roads through the town of Stellenbosch. Four way stops are simple concepts founded on relatively simple rules of engagement. However a series of observations conducted in 2010 evidenced significant levels of conflict between vehicles, and between vehicles and other road users. The study identified a high level of contravention of the yielding rules associated with a four way stop configuration, suggesting either that drivers are unaware of the yielding convention or are operating wilfully. The behaviour of pedestrians and cyclists was also examined but has been omitted from this paper because of space constraints.

Abstract: Ambitious targets and action are needed to reduce road fatalities globally. The iRAP vision is for a world free of high risk roads and this paper outlines the social and economic business case for this investment. An estimated 1,735,000 deaths and serious ...

This research article reports on a study conducted on 2022 and 2023 to
measure air quality in five selected locations in Rajshahi, Bangladesh. According to air pollution control rules in Bangladesh, yearly and daily average concentration of PM2.5 in ambient air should be maximum 35 μg/m3 and 65 μg/m3. Similarly yearly and daily average concentration of PM10 in ambient air should be maximum 50 μg/m3 and 150 μg/m3. PM2.5 concentration was found significantly higher in all locations. Maximum PM2.5 was found at Talaimari, 75 μg/m3. Average high concentration of PM2.5 and PM10 in Rajshahi city was 90 μg/m3 and 231 μg/m3 November, dry season. The study highlights the need for regulations to control air pollution in Bangladesh.

Pertambahan jumlah kendaraan bermotor yang pesat tanpa diikuti dengan peningkatan sarana dan prasarana transportasi akan berdampak terhadap turunnya kinerja persimpangan dan mempengaruhi pergerakan arus lalu lintas. Salah satu persimpangan bersinyal dengan tingkat arus lalu lintas yang padat dan sering terjadi kemacetan adalah Simpang Surabaya Kota Banda Aceh. Saat ini fasilitas ruang henti khusus (RHK) sepeda motor telah dibangun di persimpangan tersebut. Penelitian ini bertujuan untuk mengevaluasi efektivitas RHK di Simpang Surabaya. Tahapan penelitian meliputi survei geometrik persimpangan, volume, kinerja persimpangan, dan kondisi RHK. Hasil penelitian menunjukkan bahwa penerapan RHK belum efektif, namun keberadaan RHK telah mempengaruhi kapasitas persimpangan. Ditinjau dari tingkat keberhasilan dan kecukupan, penerapan RHK masih terbatas pada beberapa lengan persimpangan yang diakibatkan tingginya jumlah kendaraan sepeda motor, penumpukan sepeda motor yang tidak teratur, dan terjadi kemacetan panjang.

High urbanization rate and Economic development have caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at congestion places are a few to mention. Many literatures have revealed that road traffic congestions are caused by inadequate infrastructures, long signal cycle time and poor traffic management, such as incapable roads, inefficient public transit, and high travel demand. The research study was focused on the effect of traffic congestion on average time delay at selected signalized road intersection in Addis Ababa. The study area was Hager Astedadrerroad traffic signal intersection. The methodology that has been employed for the study was a quantitative descriptive research design method. The data needed were; road geometry data, signal data, traffic vehicles flow data including the pedestrian data were collected on peak hours (with 15minutes interval) from 7:30-9:30 AM and from 5:30-7:30 PM for the four consecutive working days. Data of traffic classes were extracted manually on a separate worksheet. The volume of each vehicle category was converted to the same vehicle category using passenger car unit (PCU) of each vehicle class. Data analysis and processing have been performed using SIDRA (Signalized and Unsignalized Intersection Design and Research Aid) intersection software in order to know the traffic flow condition at the intersection. The result of average time delay was used to know the corresponding level of service and operational performance of the intersection. The outcomes of the research work minimize average time delay by adopting different improving strategies that range from low-cost measures such as improvements to signal timing and phase numbers, to high-cost measures such as intersection reconstruction, which be applied in the study area after knowing the amount of average time delay as well as the types of the level of service within the intersection area.

Road traffic accident was one of the severe problems which are affecting once's country and leading to death, injuries and property damage resulted in economic loss. The objective of this research was to investigate the effects of Human behaviors and Geometric factors in road traffic accidents along the road of Sululta-Fiche, which is located in Northern Shewa of Oromia region. Both probability sampling and non-probability sampling techniques were applied. The primary data were obtained from site observation of blackspot locations. While the secondary source of data was taken from records compiled by North Shewa traffic office and Oromia Special Zone Surrounding Finfinne traffic Office. A descriptive and analytical design methods were used in this research, while the results were displayed by graphs, tables and pie charts. From the study, the status of road traffic accident showed that there were dramatic increased of accidents every year within the study period. A total of 830 crashes occurred in the past three years. From this, 237 accidents happened in 2012, 279 accidents in 2013, and 314 accidents in 2015. From the traffic police report analysis, there were 41 locations in Sululta Town, and 70 locations in the Sululta Wereda, where those accidents happened. Based on the results of this research using priority value approach, there were 12 selected locations in Sululta Town and 10 chosen locations in Sululta Wereda. Therefore, it is concluded that the significant factor in traffic accidents along Sululta-Fiche road was the driver errors such as over-speeding, night driving and driving without attention, and it was followed by the geometric factors. These road deficiencies contributory to some errors of the drivers, were inadequate road width, insufficient sight distance, and narrow bridge at sag curves and improper intersection design. Based on the findings of the study, some of the countermeasures recommended to reduce the road traffic accidents are provision of speed limit signs to forewarn drivers, installation of speed barkers and rumble strips, widening the lane width of pavement, maintenance of deteriorated road, repair of the road signs and provision of adequate sight visibility for drivers.

Principal arterial class streets must move large traffic volumes while providing limited property access. Guidelines for median design and other characteristics that will maintain traffic flow potential are needed. Without such guidelines, principal arterials, over time, tend to lose traffic flow potential at the expense of property access functions. These guidelines are being developed as median selection criteria that consider flush medians with no left-turn lanes, flush medians with left-turn lanes, and raised medians with limited median openings.

Urban arteria1 streets and highways provide highway users with access to property and opportunities for connection with other streets or highways. In many cases, property access and route changes are accomplished through left-turn maneuvers. The efficienc y and safety with which left-turns can be accomplished is heavily dependent upon the type of median incorporated into the street or highway. Although a variety of median concepts have been used, many questions regarding the relative desirability of median types remain unanswered. This study has attempted to provide answers to, at least, some of these questions.

The aim of this paper is to present four strategies to increase the accuracy and speed of optimization of truss structures under the constraint of Structural System Failure Probability (SSFP). In the first strategy based on the probability rules, a criterion is defined to avoid producing many correlated paths and obtain more accurate upper bound of SSFP. In the second strategy, the force method formulation is improved and employed to analyze trusses with different topologies. In the third strategy two intelligent agents are utilized to identify the repeated paths and determine the fitness of the best chromosomes in each generation. Using the fourth strategy, the chromosomes, whose SSFP is much larger or smaller than the allowable value, are identified during the analysis and the analysis is terminated at that stage.

The Information and Communication Technology (ICT) industry is responsible for a non-negligible proportion of the world's global energy consumption. Unfortunately, the energy usage of the Internet will continue to rise due to the rapid growth in the number of connected devices and bandwidth intensive applications. In addition, networks are nowadays over-provisioned to provide redundancy and to preserve Quality of Service (QoS) during peak periods. This means current networks are designed to handle the "worst-case" scenario in terms of failures and traffic demands. In other words, they are not designed to be energy efficient. However, many works have shown that traffic exhibits diurnal patterns that correspond to business hours and weekends. This observation and the dire need to conserve energy have spurred intense research efforts into green approaches that consolidate traffic onto the minimal number of links/switches/routers during off-peak periods. In particular, researchers have designed many green or energy-aware traffic engineering (TE) techniques that jointly optimize energy savings and QoS constraints such as maximum link utilization, and end-to-end delays. This thesis contains a number of novel green TE techniques. First, it studies green TE techniques in Multi-Protocol Label Switching (MPLS) networks. Approaches in this area aim to establish as many arriving Label Switched Path (LSP) requests as possible while utilizing the minimum number of links/routers. However, II Abstract no one has quantified these LSP establishment approaches in terms of the number of accepted LSP requests and the resulting energy savings. Therefore, this thesis studies six heuristics and proposes a novel metric that considers both energy savings and acceptance rates. In addition, it proposes a simple heuristic that selects paths that contain already established links and use the fewest number of new links. Second, this thesis studies the controller placement problem in software defined networks (SDNs). Unlike past works, the aim is energy efficiency. Specifically, current solutions have only considered the placement of controllers and Switch-to-Controller (S2C) association such that the delay between a switch and its controller is within a given bound and controllers have a similar load. However, existing works have not jointly optimized S2C association and energy consumption. This thesis fills this gap and presents the first green TE method for SDNs. In particular, this thesis contains an algorithm that selects S2C paths that result in the lowest latency whilst using only the minimal number of links. Links that do not belong to any selected paths are then powered off. The proposed solution also guarantees that controllers have a similar number of associated switches. Thirdly, this thesis studies the impact of green TE methods on the Border Gateway Protocol (BGP) and proposes two novel BGP-aware TE techniques. This is a significant investigation because BGP is the "glue" used by Autonomous Systems (ASes) to advertise reachability information. Past works have shown that hot-potato routing changes have many negative effects on BGP. Hence, it is important that existing green TE methods do not trigger these changes. To this end, this thesis presents the first study that quantifies the effects that green TE approaches have on the operation of BGP. Experimental results show that green TE techniques cause an increase in the percentage of hot-potato routing changes and the proportion of rerouted traffic. Motivated by these results, this thesis proposes two novel BGPaware approaches that can be used to reduce energy consumption while minimizing any impacts on the operation of BGP.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8282.

Performance measure approach (PMA) is a method for evaluating the probabilistic constraints in reliability-based design optimization of structures. The advanced mean-value (AMV) method is suitable for PMA, simply and efficiently. The iterative AMV scheme could be yielded to unstable solutions such as periodic-oscillation and chaos for highly nonlinear performance functions. In the present paper, an improved stability transformation method (ISTM) is proposed for appropriate convergence of nonlinear performance functions. This iterative approach has been established based on a suitable stepsize between one and zero that is simply calculated on the basis of the new results of AMV scheme and the previous results of the improved stability transformation iterative formula. The descent condition was applied in the iterative sequences of the ISTM to achieve stable convergence. The results of several nonlinear performance functions in reliability-based design optimization demonstrate that the ISTM is laded to control instability solutions of PMA and also, it is more robust than AMV and more efficient that stability transformation method in structural problems with nonlinear performance functions.

Recurring congestion on highways is the primary cause of traffic congestion in the urban traffic system while jams on merging sections are the worst section along the expressway. Due to the presence of heavy congestion in the site of University of Technology, this study aims to discover the traffic characteristics of this site to determine the appropriate solutions. Therefore, this study selects a merging section on Mohammed Al-Qassim expressway to investigate some characteristics of such a section in Iraq. Field data have been collected from this site for 4 h. The data were collected from video cameras installed along the expressway in Baghdad city which is called Mohammed Al-Qassim Expressway. These data present flow of upstream and ramp. The Advanced Interactive Microscopic Simulator for Urban and Non-Urban Networks (AIMSUN) program was also adopted to investigate other characteristics which are difficult to get such as speed and occupancy for the current case. The results showed that the simulated and real data significantly corresponded. In this study, the AIMSUN program received recognition by utilizing Geoffrey E. Havers a method for comparing two sets of traffic volumes that are used in traffic engineering, traffic forecasting, and traffic modeling as it was discovered to be comparable to reality, and the road management was then enhanced by the addition of ramp metering and cycle (green) time control.