Characteristics and Prediction of Traffic Accident Casualties In Sudan Using Statistical Modeling and Artificial Neural Networks

Road traffic accident(RTA)casualties in Sudan are among the major causes of death in the age group of 21 to 60.with 61%fatalities.The fatality rate of 35 per 10,000 vehicles is among the highest in the world despite the low car ownership of 1 vehicle to 100 persons.This paper presents accident characteristics and considers road safety management.Crucial issues discussed in the paper include prediction and safety measures.The paper applies Artificial Neural Network(ANN)and regression techniques to comparatively predict traffic accident casualties.Both approaches modeled accident casualties using historical data on population,number of registered cars and other related factors from 1991 to 2009.Comparison of predictions with recorded data was very favorable.Predictions during 2010-2014 were determined using projected values for the same predictor variables.ANN forecasts provided the best fit for the data with a maximum difference of 1.84%between predictions and observed data.The study demonstrated that ANNs provide a powerful tool for analysis and prediction of accident casualties.The major causes of accidents were attributed to driver behaviour,vehicle fleet and conditions,road network defects,speed-limit violation,negligence of seat-belt usage and lack of traffic-law enforcement.

Deriving Operational Origin-Destination Matrices From Large Scale Mobile Phone Data

A method is presented in this work that integrates both emerging and mature data sources to estimate the operational travel demand in fine spatial and temporal resolutions.By analyzing individuals’mobility patterns revealed from their mobile phones,researchers and practitioners are now equipped to derive the largest trip samples for a region.Because of its ubiquitous use,extensive coverage of telecommunication services and high penetration rates,travel demand can be studied continuously in fine spatial and temporal resolutions.The derived sample or seed trip matrices are coupled with surveyed commute flow data and prevalent travel demand modeling techniques to provide estimates of the total regional travel demand in the form of origindestination(OD)matrices.The methodology is evaluated in a series of real world transportation planning studies and proved its potentials in application areas such as dynamic traffic assignment modeling,integrated corridor management and online traffic simulations.

Coordinated Ramp Metering and Intersection Signal Control

The operations of freeway ramp metering and urban traffic network signal control are independent in most areas.Such situation may cause some conflict between traffic streams of the two subsystems,or,at least,their dynamic interactions have not been taken into account from an overall system viewpoint.Traffic performance can be improved if the controls of these two sub-networks are integrated.This paper proposes a novel signal control strategy for the feeding intersection and a coordination strategy for integrating it with the corresponding freeway onramp metering.UP ALINEA with queue-overwrite is used for the ramp metering.A signal optimization,which takes into account the available ramp space and traffic demand,is developed for intersection signal control.A calibrated micro-simulation is used to compare the proposed control/coordination strategies and current control plans in the field.Simulation result shows that,even though the overall system performance only gets a marginal improvement,intersection delay reduces significantly.

Cohesive Soil Stabilized Using Sewage Sludge Ash/Cement and Nano Aluminum Oxide

In order to improve soft soil strength,a mixture of incinerated sewage sludge ash(SSA)and cement was applied as a soil stabilizer.The intended mix ratio for SSA and cement was 3:1.A-6 clay was selected as the untreated soil.In this study,15%of clay soil was replaced by SSA/cement to produce the treated soil specimens.Then,four different volumes,namely 0,1,2,and 3%,of nano-Al_(2)O_(3) were mixed with the treated soil as an additive.Tests such as compaction,pH values,Atterberg limits,unconfined compressive strength(UCS),swell potential,California bearing ratio(CBR),and permeability were performed.The results indicate that both UCSs and CBR values of untreated soil were greatly improved by the use of 15%SSA/cement.Moreover,a 1%addition of nano-Al_(2)O_(3) enhanced the treated soil in terms of both UCS and CBR values.Furthermore,the swell potential was effectively reduced by the use of 15%SSA/cement as compared with untreated soil and the 1%nano-Al_(2)O_(3) additive fraction offered the best performance.From this study,we conclude that 15%of SSA/cement replacement could effectively stabilize A-6 clay soil,and 1%of nano-Al_(2)O_(3) additive may be the optimum amount to add to the soil.

Queue Storage Design for Metered On-Ramps

Queue storage at a metered freeway on-ramp is an essential design element for metered on-ramps to prevent on-ramp queue from extending beyond on-ramps.In this paper,various existing methodologies that are used to size the queue storage at metered on-ramps were first reviewed.It was found that queue storage sized using 7%of peak hour on-ramp demand is widely accepted in practice.A limited dataset collected in California helps provide some reality check for this method.It is recommended that queue storage be recognized as an indispensable design element at metered on-ramps,and detailed sizing guidance be developed in the highway geometric design policy of the American Association of State Highway and Transportation Officials(AASHTO).

The Weaving Length Limit for Short Free Onramps

Onramp merging may be difficult if the onramp weaving/merging length is too short because a driver may find that even merging behind a neighboring large truck on the adjacent outside lane may not be completed safely.Because of insufficient weaving length for onramp acceleration,a slow merged vehicle may be rear-ended by a following vehicle on the outside lane when speed differential between the onramp vehicle and the following vehicle is relatively high.Nevertheless,short onramps at occasions are designed and built when right of way is constrained possibly by a variety of issues.The design onramp weaving length hasn’t been well explained physically in various existing guidelines or design manuals.Recently,a design paradigm,where human factors,vehicle dynamics,tire-road friction,and the onramp merging scenarios are integrated into a single framework,has been developed to resolve this merging difficulty.In this paper,the lower limit recommended for onramp weaving length needed for a driver to merge into the freeway traffic successfully is determined based on the physical solutions derived from the paradigm and a physical constraint for avoiding potential rear-end collisions between the slow merged vehicle and the following vehicle on freeway.This weaving length limit sets the minimal weaving length for safer free onramp merging and guides the practitioners/designers who encounter design situations where freeway right of way at onramp is limited.

Utilization of Ripe Coconut Fiber in Stone Matrix Asphalt Mixes

Stone Matrix Asphalt(SMA)is a gap graded mix;characterized by higher proportion of coarse aggregate,lower proportion of middle size aggregate and higher proportion of mineral filler.In the present laboratory study,commonly available one conventional VG 30 bitumen and another modified binder,namely CRMB 60 have been used along with a non-conventional natural fiber,namely coconut fiber which is abundantly available in India to provide improved engineering properties and at the same time preventing the usual draining of binder in SMA.The role of a particular binder and fiber with respect to their concentrations in the mix is studied for various engineering properties.Marshall procedure has been followed to determine the optimum binder and optimum fiber contents and also to study the relative advantages of fiber addition in the SMA mixtures.Thereafter,the engineering properties under both static as well as repeated load conditions and moisture susceptibility characteristics have been studied.It is observed that only a marginal 0.3%coconut fiber addition brings significant improvement in the engineering properties of SMA mixes.

Prediction of Marshall Parameters of Modified Bituminous Mixtures Using Artificial Intelligence Techniques

This study presents the application of artificial neural networks(ANN)and least square support vector machine(LS-SVM)for prediction of Marshall parameters obtained from Marshall tests for waste polyethylene(PE)modified bituminous mixtures.Waste polyethylene in the form of fibres processed from utilized milk packets has been used to modify the bituminous mixes in order to improve their engineering properties.Marshall tests were carried out on mix specimens with variations in polyethylene and bitumen contents.It has been observed that the addition of waste polyethylene results in the improvement of Marshall characteristics such as stability,flow value and air voids,used to evaluate a bituminous mix.The proposed neural network(NN)model uses the quantities of ingredients used for preparation of Marshall specimens such as polyethylene,bitumen and aggregate in order to predict the Marshall stability,flow value and air voids obtained from the tests.Out of two techniques used,the NN based model is found to be compact,reliable and predictable when compared with LS-SVM model.A sensitivity analysis has been performed to identify the importance of the parameters considered.

Communication’s Role in Safety Management and Performance for the Road Safety Practices

Communication among organizations could play an important role in increasing road safety.To get in-depth knowledge of its role,this study measured managers’and employees’perceptions of the communication’s role on six safety management and performance criteria for road safety practices by conducting a survey using a questionnaire among 165 employees and 135 managers.Path analysis using AMOS-19 software shows that some of the safety management road safety practices have high correlation with the safety performance,namely,from the six antecedents,only the safety training and safety promotion,closely correlate with the safety motivation,and only safety commitment,safety communication and feedback have close relations with the safety knowledge and safety behavior compliance,and only safety feedback has effective relations with the safety participation.Safety feedback is identified as the most important safety management issue to road safety practices and it would predict the level of safety knowledge,safety motivation,safety compliance and safety participation.The results of this study would help the concerned agencies/orgaizations in improving their ability to assess the road safety indicators and to the future development of the safety performance management for road safety practices in these agencies.

An Importance Segregation Based Multi-Objective Optimization Model for Traffic Safety Improvement Countermeasure Selection

This paper presents a multi-objective optimization model to decide effective and beneficial portfolio for implementing traffic safety improvements under budgetary constraints.Different from the conventional multi-objective approaches,the proposed model segregates decision criteria into different importance levels and designs a successive optimization approach to obtain the final solution(s).Such modeling features offer the advantages to:1)prevent the arbitrariness for transportation agencies to determine weights for decision criteria;2)remedy the deficiency of over-weighting less important criteria in the traditional multi-objective optimization approach;and 3)minimize the number of potential solutions for final decision by transportation agencies with enhanced screening of the sub-optimal solutions.Case study results reveal that the proposed model is efficient not only for deciding the most suitable traffic safety countermeasure for a specific site,but also for determining the plans for implementing multiple countermeasures among multiple sites given the budget constraint.Comparative study results have also indicated that the proposed model outperforms the traditional criteria in objectively selecting traffic safety improvements in a multi-criteria decision-making process.The clarity of model inputs and the interpretation of results with respect to different selection criteria offer its best potential to be used as an effective decision-support tool for transportation authorities to assess and refine their safety improvement investments.

A Temporal Domain Decomposition Algorithmic Scheme for Large-Scale Dynamic Traffic Assignment

With emergent interest of Simulation-Based Dynamic Traffic Assignment(SBDTA)in the field of transportation network modeling,deployment of SBDTA models for traffic operations and transportation planning have increased significantly in recent years.In parallel,research and development of innovative approaches of the SBDTA model have enhanced the quality of both the assignment component,i.e,improvement of convergence quality of the Dynamic User Equilibrium(DUE)problem,and the traffic simulation element.However,computational requirement remains to be one of the great challenges for DTA implementations on large-scale networks with a long analysis period.This paper presents a temporal decomposition scheme for large spatial-and temporal-scale dynamic traffic assignment,in which the entire analysis period is divided into Epochs.Vehicle assignment is performed sequentially in each Epoch,thus improving the model scalability and confining the peak run-time memory requirement regardless of the total analysis period.A proposed self-turning scheme adaptively searches for the run-time-optimal Epoch setting during iterations regardless of the characteristics of the modeled network.Extensive numerical experiments confirm the promising performance of the proposed algorithmic schemes.

A Comparison of Floating Car vs.Loop Detector Estimated Freeway Travel Time Delay

Floating car-and loop detector-based methods are two different types of methods frequently used to collect travel time delay information across a freeway network.Sometimes,it is necessary to use them jointly to achieve the necessary freeway network coverage,due to the high labor costs for the floating car-based method and the indispensability of sufficient network instrumentation for the loop detector-based method.For example,both floating car-and loop detector-based methods were once used in the Highway Congestion Monitoring Program in the California Department of Transportation.It is therefore necessary to evaluate whether these two types of methods estimate similarly in terms of total travel time delay.To this end,corresponding delay information estimated using both types of methods from 37 freeway segments in the Greater Sacramento Area were collected and compared.It was found that these two types of methods do not estimate similarly in terms of total segment travel time delay.The mean absolute relative difference(MARD)can be as high as 78%,especially when delay is defined using a lower reference speed,such as 56 km/h.However,in terms of total segment travel time,the loop detector and the modified floating car method estimated similarly.The MARD is 19%.It was also found that the estimation from the different methods did correlate fairly well,which provides a means of conversion when different methods are used to monitor the total delay across a freeway network.As a spin-off,it was also found that a 1.5 km spacing of loop detectors is sufficient to achieve the 19%MARD as compared with the modified floating car method in terms of total travel time estimation.

A Discussion on the Current MUTCD Standards on Traffic Control Signals for Freeway Entrance Ramps

In Section 4I.02 of the newly published Manual on Uniform Traffic Control Devices(MUTCD),standards were specified for the placement of signal heads for traffic control signals at freeway entrance ramps,or ramp meters.For simultaneous operations,i.e.when ramp control signals are operated such that green signal indications are always displayed simultaneously to all of the lanes on the ramp,a minimum of two signal faces per ramp shall face entering traffic.For staggered operations,i.e.the ramp control signal are operated such that green signal indications are not always displayed simultaneously to all of the lanes on the ramp,one signal face shall be provided over the approximate center of each separately-controlled lane.Based on a nation-wide survey,it was realized that the two standards did not fully reflect the state-of-the-practice with respect to ramp metering operations.Due to the lack of significant conflicting movements at ramp meters,for any on-ramp lane,a minimum of one overhead mounted,or one upper and one lower roadside-mounted signal face is sufficient to control the metering operations.The minimum necessary number of signal faces changes according to the total number of lanes,how the signal faces are mounted(overhead or roadside mounting),and how the meters are operated(simultaneous or staggered).Suggestions are made to revise the two standards to better reflect the current nation-wide practices,and better consider the specific operational needs for ramp meters.

An Agent-Based Solution Framework for Inter-Block Yard Crane Scheduling Problems

The efficiency of yard operations is critical to the overall productivity of a container terminal because the yard serves as the interface between the landside and waterside operations.Most container terminals use yard cranes to transfer containers between the yard and trucks(both external and internal).To facilitate vessel operations,an efficient work schedule for the yard cranes is necessary given varying work volumes among yard blocks with different planning periods.This paper investigated an agent-based approach to assign and relocate yard cranes among yard blocks based on the forecasted work volumes.The goal of our study is to reduce the work volume that remains incomplete at the end of a planning period.We offered several preference functions for yard cranes and blocks which are modeled as agents.These preference functions are designed to find effective schedules for yard cranes.In addition,we examined various rules for the initial assignment of yard cranes to blocks.Our analysis demonstrated that our model can effectively and efficiently reduce the percentage of incomplete work volume for any real-world sized problem.

Application of Different HSI Color Models to Detect Fire-Damaged Mortar

To obtain a better understanding of the effect of vehicle fires on rigid pavement,a nondestructive test method utilizing an ordinary digital camera to capture images of mortar at five elevated temperatures was undertaken.These images were then analyzed by“image color-intensity analyzer”software.In image analysis,the RGB color model was the basic system used to represent the color information of images.HSI is a derived-color model that is transformed from an RGB model by formulae.In order to understand more about surface color changes and temperatures after a vehicle fire,various transformation formulae used in different research areas were applied in this study.They were then evaluated to obtain the optimum HSI model for further studies of fire-damaged mortar through the use of image analysis.

An Experimental Study on Assessment of Pavement Interlayer Bond Strength

It is a common practice to apply a tack coat usually in the form of bituminous emulsion over an existing bituminous surface before laying another bituminous layer.The boundary between these two consecutive bituminous layers is the layer interface and the pavement stress distribution is highly influenced by the adhesion conditions at this interface.Poor adhesion causes adverse effects on the structural strength of the pavement system.A number of premature failures such as slippage failure and delamination failures result thus defeating the construction objectives.In the absence of a standard method and apparatus to address this field problem,an attempt has been made in this study to develop a simple testing arrangement to be used in a laboratory to determine the interlayer bond strength.Normal Marshall procedure has been used to prepare the specimens consisting of two different types of bituminous materials in lower and upper part of the same specimen.It is observed within the scope of study that Cationic rapid setting(CRS-1)emulsion applied at 0.25 Kg/m^(2) offers the best results of interlayer bond strength.

Design of Driving Behavior Pattern Measurements Using Smartphone Global Positioning System Data

The emergence of new technologies such as GPS,cellphone,Bluetooth device,etc.offers opportunities for collecting high-fidelity temporal-spatial travel data in a cost-effective manner.With the vehicle trajectory data achieved from a smartphone app Metropia,this study targets on exploring the trajectory data and designing the measurements of the driving pattern.Metropia is a recently available mobile traffic app that uses prediction and coordinating technology combined with user rewards to incentivize drivers to cooperate,balance traffic load on the network,and reduce traffic congestion.Speed and celeration(acceleration and deceleration)are obtained from the Metropia platform directly and parameterized as individual and system measurements related to traffic,spatial and temporal conditions.A case study is provided in this paper to demonstrate the feasibility of this approach utilizing the trajectory data from the actual app usage.The driving behaviors at both individual and system levels are quantified from the microscopic speed and celeration records.The results from this study reveal distinct driving behavior pattern and shed lights for further opportunities to identify behavior characteristics beyond safety and environmental considerations.

Optimal Retrofit Scheme for Highway Network under Seismic Hazards

Many older highway bridges in the United States(US)are inadequate for seismic loads and could be severely damaged or collapsed in a relatively small earthquake.According to the most recentAmerican Society of Civil Engineers’infrastructure report card,one-third of the bridges in the US are rated as structurally deficient and many of these structurally deficient bridges are located in seismic zones.To improve this situation,at-risk bridges must be identified and evaluated and effective retrofitting programs should be in place to reduce their seismic vulnerabilities.In this study,a new retrofit strategy decision scheme for highway bridges under seismic hazards is developed and seamlessly integrate the scenario-based seismic analysis of bridges and the traffic network into the proposed optimization modeling framework.A full spectrum of bridge retrofit strategies is considered based on explicit structural assessment for each seismic damage state.As an empirical case study,the proposed retrofit strategy decision scheme is utilized to evaluate the bridge network in one of the active seismic zones in the US,Charleston,South Carolina.The developed modeling framework,on average,will help increase network throughput traffic capacity by 45%with a cost increase of only$15million for the Mw 5.5 event and increase the capacity fourfold with a cost of only$32m for the Mw 7.0 event.

The Sight Distance Issues with Retrofitted Single-Lane HOV Facilities

It is well-known that obstruction inside a highway horizontal curve will lead to impaired sight distance.Highway alignment design standards in terms of the minimum horizontal curve radius are specified to allow for adequate stopping sight distance at given design speeds.For a singlelane HOV facility,inside curve obstruction may occur no matter when the facility curves to the left(per travel direction)or right.A unique situation that calls for special attention is that the adjacent mixed-flow lane traffic,once queued,may become sight obstruction.Calculations indicated that such obstruction may govern the minimum curve radius design as long as the left shoulder is not less than 0.92 m,when the HOV lane is contiguous to the mixed-flow lanes.Such governance may necessitate design speed reduction,horizontal and cross-section design adjustment,or both.

Long-term User and Community Impacts of High-speed Rail in the United States’Midwest Corridor

This study contributes new insights in the debate over the viability of high-speed rail(HSR)in the United States and the value proposition for government investment.The modeling focus of this study is two-fold,and the modeling approach makes a case for a fundamental shift from the current perspective of HSR viability.First,the user and community impact assessment of HSR is conducted in the same manner as traditional transportation system evaluation(i.e.,vehicle operating costs(VOC),travel time,safety,emissions,and energy consumption)to provide comparable conclusions regarding intercity transportation alternatives.Second,the model presented in this study analyzes both ridership and impacts within the same systematic framework to assess the long-term impacts on the individual transportation modes,total system metrics,and efficacy of alternate policies.Using this model,decision-makers can introduce various externalities to determine both the ideal and problematic conditions for the viability of a new HSR system.