Naveen Veeramisti

Assessment of Economic Impacts of Vehicle Miles Traveled Fee for Passenger Vehicles in Nevada

This study evaluated the effectiveness and equity of a fee for vehicle miles traveled (VMT) for passenger vehicles in Nevada. In the evaluation of the fees effectiveness, the collection capabilities, as well as the fees impact on the number of miles users drove, were considered. Equity was evaluated by considering the impact of the VMT fee on various population groups on the basis of socioeconomics, demographics, household type, location, and ownership of fuel-efficient vehicles. To estimate the impacts on various VMT fees, a linear regression model was developed with the use of data from the 2009 National Household Travel Survey, which provided a mechanism to estimate VMT in Nevada as a function of the cost to drive, among other characteristics. The effectiveness and the equity of two alternative VMT fees were compared with the existing fuel tax system. These fees were calculated on the basis of the average fuel efficiency of vehicles in Nevada and the historical revenue from the state fuel tax. In general, a VMT fee of 3.3 cents per mile seemed to be more effective than both the existing fuel tax and a VMT fee of 2.91 cents per mile. Although the 3.3 cents per mile fee had a slightly greater impact on various population groups, its equitable distribution of the tax burden among 71.1% of households created a small average cost increase of just 0.37% per household. Thus, a 3.3 cents per mile fee would provide the necessary revenue without significantly affecting Nevada households.

Development of a Visualization System for Safety Analyst

The AASHTO software Safety Analyst is a state-of-the-art tool with significant capabilities and advanced analytical methods for comprehensive analysis and management of highway safety. However, this tool does not provide visualization capabilities. To address that limitation, this study proposes a visualization system for Safety Analyst that provides graphical displays, including location and color-coded information for each module. In addition, the system generates charts, which have various degrees of resolution and aggregation; tables; and a report summarizing safety performance measures. The system can use Google Maps or ESRI ArcGIS to generate the graphical displays. The advantage of using Google Maps is its simplicity; in contrast, the ArcGIS display provides additional modeling and computing capabilities of the GIS framework. All displays are very intuitive and can be customized according to user needs. Because the user can see the locations of every specific site, the displays facilitate analysis as well as the decision-making process. The visualization system interacts with Safety Analyst so that the user can access all tools and data throughout the entire modeling and analysis process.

Development of a Comprehensive Database System for Safety Analyst

This study addressed barriers associated with the use of Safety Analyst, a state-of-the-art tool that has been developed to assist during the entire Traffic Safety Management process but that is not widely used due to a number of challenges as described in this paper. As part of this study, a comprehensive database system and tools to provide data to multiple traffic safety applications, with a focus on Safety Analyst, were developed. A number of data management tools were developed to extract, collect, transform, integrate, and load the data. The system includes consistency-checking capabilities to ensure the adequate insertion and update of data into the database. This system focused on data from roadways, ramps, intersections, and traffic characteristics for Safety Analyst. To test the proposed system and tools, data from Clark County, which is the largest county in Nevada and includes the cities of Las Vegas, Henderson, Boulder City, and North Las Vegas, was used. The database and Safety Analyst together help identify the sites with the potential for safety improvements. Specifically, this study examined the results from two case studies. The first case study, which identified sites having a potential for safety improvements with respect to fatal and all injury crashes, included all roadway elements and used default and calibrated Safety Performance Functions (SPFs). The second case study identified sites having a potential for safety improvements with respect to fatal and all injury crashes, specifically regarding intersections; it used default and calibrated SPFs as well. Conclusions were developed for the calibration of safety performance functions and the classification of site subtypes. Guidelines were provided about the selection of a particular network screening type or performance measure for network screening.

Forecasting Performance Measures for Traffic Safety Using Deterministic and Stochastic Models

Traffic-safety performance measures required by the Moving Ahead Progress in 21st Century (MAP-21) act were forecasted in this study to facilitate the reduction of fatalities and serious injuries. Given the lack of exposure data (e.g., traffic counts), time series were used to conduct the forecast. Deterministic and stochastic models were applied using four independent and univariate time series from the crash data collected by the Nevada Department of Transportation. The best model specification was obtained using root mean square error and mean absolute percent prediction error as goodness of fit. Among several deterministic models evaluated in this study, the Winter-additive model for seasonal data and the Damped-trend model for non-seasonal data provided adequate forecasts. In the case of stochastic models, for non-seasonal data, an Autoregressive Integrated Moving Average (ARIMA) model provided acceptable results. However, the absence of adequate data likely precludes an appropriate estimation using the ARIMA model. For seasonal data, a Seasonal Autoregressive Integrated Moving Average (SARIMA) model provided the best forecast measures. The stochastic SARIMA(0,0,5)(0,1,1)12 model, an improved model, had a preferred fit for predicting the number of fatalities and serious injuries in Nevada over a five-year horizon. The SARIMA model could be an appropriate statistical model to predict fatalities and serious injuries as required by MAP-21.

Traffic and Driving Simulator Based on Architecture of Interactive Motion

This study proposes an architecture for an interactive motion-based traffic simulation environment. In order to enhance modeling realism involving actual human beings, the proposed architecture integrates multiple types of simulation, including: (i) motion-based driving simulation, (ii) pedestrian simulation, (iii) motorcycling and bicycling simulation, and (iv) traffic flow simulation. The architecture has been designed to enable the simulation of the entire network; as a result, the actual driver, pedestrian, and bike rider can navigate anywhere in the system. In addition, the background traffic interacts with the actual human beings. This is accomplished by using a hybrid mesomicroscopic traffic flow simulation modeling approach. The mesoscopic traffic flow simulation model loads the results of a user equilibrium traffic assignment solution and propagates the corresponding traffic through the entire system. The microscopic traffic flow simulation model provides background traffic around the vicinities where actual human beings are navigating the system. The two traffic flow simulation models interact continuously to update system conditions based on the interactions between actual humans and the fully simulated entities. Implementation efforts are currently in progress and some preliminary tests of individual components have been conducted. The implementation of the proposed architecture faces significant challenges ranging from multiplatform and multilanguage integration to multievent communication and coordination.

Evaluation of the Effectiveness of a HAWK Signal on Compliance in Las Vegas Nevada

There is a continuous large number of crashes involving pedestrians in Nevada despite the numerous safety mechanisms currently used at roadway crossings. Hence, additional as well as more effective mechanisms are required to reduce crashes in Las Vegas, in particular, and Nevada in general. A potential mechanism to reduce conflicts between pedestrians and vehicles is a High-intensity Activated crossWalK (HAWK) signal. This study evaluates the effects of such signals at a particular site in Las Vegas. Video data were collected using two cameras, facing the eastbound and westbound traffic. One week of video data before and after the deployment of the signal were collected to capture the behavior of both pedestrians and drivers. T-test analyses of pedestrian waiting time at the curb, curb-to-curb crossing time, total crossing time, jaywalking events, and near-crash events show that the HAWK system provides significant benefits.

Towards a realistic traffic and driving simulation using 3D rendering

The objective of this research is to provide a deployable driving simulation framework with the focus on increasing modeling realism. A traffic and driving simulator concept was developed using Open Street Map (OSM) for the three-dimensional (3D) generation of the corresponding visualization module. The proposed framework includes Glosm, a hardware-accelerated OpenGL based on OSM. Glosm provides stable 3D generation of a virtual vehicular urban system using OSM data and a real-time first-person viewer. First, a 3D car model was implemented in Glosm. Then, a driving and traffic simulator (without graphics) was developed including all the required functions for representation and motion handling within Glosm. Initially, a way of testing was defined and implemented for all future development of the navigation handler. The goal was to determine the configuration of the OSM-type road network from a given position in order to compute the navigation trajectories. The data system of OSM was highly unsuitable for this application because the roads are included in the same layer as other objects. Unity is an alternative to Glosm. Some information about Unity is provided with recommendations for future research.