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The Federal Highway Administration (FHWA) and the National Highway Traffic Safety Administration (NHTSA) published the Speed Safety Camera Program Planning and Operations Guide in 2023. FHWA staff are publishing this fact sheet to introduce the content of the guide and share how State and local transportation agency practitioners can use it when considering the deployment of speed safety camera (SSC) programs as part of their comprehensive work zone safety strategies.

Innovative Density Profiling of Asphalt Pavement - Interchange Configurations: Planning-Level Analysis Tool Identifies Expected Safety Performance - Alternative Uses of the Right-of-Way - The New George Washington Memorial Parkway Byway - Speed Safety Cameras.

Eco-driving strategies based on connected and automated vehicles (CAV) technology, such as Eco-Approach and Departure (EAD), have attracted significant worldwide interest due to their potential to save energy and reduce tail-pipe emissions. In this project, the research team developed and tested a deep learning–based trajectory-planning algorithm (DLTPA) for EAD. The DLTPA has two processes: offline (training) and online (implementation), and it is composed of two major modules: 1) a solution feasibility checker that identifies whether there is a feasible trajectory subject to all the system constraints, e.g., maximum acceleration or deceleration; and 2) a regressor to predict the speed of the next time-step. Preliminary simulation with microscopic traffic modeling software PTV VISSIM showed that the proposed DLTPA can achieve the optimal solution in terms of energy savings and a greater balance of energy savings vs. computational efforts when compared to the baseline scenarios where no EAD is implemented and the optimal solution (in terms of energy savings) is provided by a graph-based trajectory planning algorithm.View the NCST Project Webpage

The U.S. Environmental Protection Agency identified the use of low rolling resistance (LRR) tires as an effective method of reducing vehicle fuel consumption, especially from heavyduty vehicles (HDV). LRR tires are important to HDV operations because fuel accounts for about 25% of operating costs, and improving fuel economy also reduces emissions of both greenhouse gases and oxides of nitrogen, a precursor to the formation of ozone, which is harmful to humans, plants, and animals. However, their adoption rate has been slow primarily due to performance uncertainties under real-world operating conditions. Previous mathematical models developed to help fleet operators estimate the impact of LRR tires on their operations have suffered from poor accuracy because they do not account for variable speed profiles in realworld HDV operations. Georgia Tech researchers have developed a new tool for fleet managers that better predicts the benefits of LRR tires under real-world conditions.View the NCST Project Webpage

This report documents the field test of Variable Speed Advisory (VSA) which is an Active Traffic Management strategy. The test site for the VSA is on State Route 78 Eastbound (SR-78E) from Vista Village Drive (in the City of Vista) to the freeway interchange point of SR-78E and U.S. Route 15 (in the city of Escondido). This test segment is a three-lane freeway with a posted speed limit of 65 mph and it has 10 on-ramps and 10 off-ramps. The project was funded by the California Department of Transportation (Caltrans) Division of Research Innovation and System Information (DRISI) under Contract Number 65A0587. Real-time traffic detector data including flow, speed, and occupancy from pre-existing loop detectors in the field test site, were transmitted via the internet by engineers at Caltrans District 11 (D11) Transportation Management Center (TMC) to a server located in the offices of California Partners for Advanced Transportation Technology (PATH). This data was then aggregated with real time speed data, captured every 30s [seconds] by radar equipment installed along with solar panel powered LED display equipment, for the display of a VSA, at 7 different sites along a 10.8 mile section of SR 78E. These two sources of data were then processed for the estimation of the overall traffic state along the corridor, which was in-turn used to calculate the VSA for each section in order to maximize overall traffic throughput through recurrent bottlenecks on SR-78E. Calculated VSA values were then rounded to multiples of 5 mph and displayed on the VSA signs. Public outreach was conducted by Caltrans D11 Public Information Office (PIO) to educate the public about the VSA test, and encourage their compliance with posted speed advisories. A publicly accessible website was also developed for the real-time display of Google Traffic, traffic state, and VSAs displayed in the field. This site was used extensively by Caltrans management, the project team, and by the public dri

The growth of the car fleet and the increase in traffic is accompanied by an increase in traffic, and in conditions of cities with historically formed buildings leads to traffic problems. It is especially evident on the sections of the road network with a large number of intersections on the motorways. They are characterized by an increase in traffic delays, queues and congestion formation, a decrease in communication speed, an increase in fuel consumption, increased triggering of vehicles. In addition, the environmental condition of the sections of the motorways is deteriorating. With the increase in the number of cars, the negative features of motorization are manifesting themselves, namely, a significant decrease in the speed of traffic flows on the road network due to traffic delays. Traffic delays and congestion are affected by a number of factors: the width of the roadway, the mode of traffic lights, the presence of parked cars along the edges of the roadway, the geographical location of the streets, traffic accidents, the driver’s psychological status, level of professional training, etc. The constant increase in the number of vehicles on city highways leads to periodic congestion of the road network. Congestion can be considered as a negative factor of active motorization in conditions of shortage of road space. Traffic congestion, like any traffic delays, leads to economic losses: the cost of time, the decrease in the efficiency of freight traffic, the increase of fuel costs, the increase in the number of accidents. Studies of traffic conditions were conducted on the street Pushkinskaya, which is classified as one of the main streets of city value. The formation of traffic flows on the main street is caused by the merger of flows from the crossroads and adjacent streets. Movement of traffic flows down the street is in the direction both to the central part of the city and in the opposite direction. This section creates difficult traffic conditions

The cost of fuel represents a major portion of the costs of operating on-road heavy-duty vehicles (HDV). Over the next couple of decades, the total energy demand from the HDV sector will likely increase due to forecasted growth in freight demand in many global markets, including the United States, and much of this energy will continue to be provided by fossil fuels. Therefore, carbon dioxide emissions from the HDV sector are also expected to increase in the absence of effective mitigating measures to reduce the sectors reliance on fossil fuels. Along with other fuel-saving technologies, the United States Environmental Protection Agency identified the use of Low Rolling Resistance (LRR) tires as an effective method of reducing fuel consumption. It is estimated that LRR tires can improve fuel economy in HDV by about 10 percent. However, adoption of LRR faces many barriers and the most fundamental of these barriers relate to potential performance uncertainties under real-world operating conditions. Previous published decision support tools developed to help fleet operators and other stakeholders estimate the fuel-savings from LRR tires have been found to have limited accuracy due to inherent transient speed profiles in real-world operating cycles.In this study, we develop a tool to predict the fleet-wide fuel-saving benefits from low rolling resistance tires. Unlike previous studies, the developed tool is applicable to both stabilized speed operations and transient speed operations. The tool is based on empirical models that estimate the fuel consumption contribution from tires as a function of vehicle payload, aerodynamic drag, road grade, duration of acceleration, duration of deceleration and, and road facility type (freeway, major arterial, and minor arterial/local road). We limited the scope of the developed tool to tractor-trailers in the U.S. heavy-duty vehicle market, because the United States has the second largest HDV market in the world and tractor-trailers a

Realtime traffic speed estimation is an important issue in urban computation. Existing approaches usually focus on exploiting the periodicity properties of the traffic speed and utilize crowdsourcing techniques to facilitate real-Time estimation. The quality of such estimation is limited in real world: 1) the accuracy of existing estimation over-relies on the probed data; 2) the accidental traffic variance is ignored; 3) existing strategies incur exhaustive usage of human workers to get fine-grained estimation results. Thus, a more intelligent RTSE approach is desired. In this paper, we propose the framework of CrowdRTSE (Crowdsourcing-based Real-Time Traffic Speed Estimation), which adopts a hybrid offline-online process to collaboratively exploit the historical and real-Time data to produce high-quality RTSE. To accomplish such a framework, we devise effective algorithms to judiciously select the best group of human workers with a constant approximation ratio, and effectively propagate the crowdsourced data with high efficiency. Comprehensive evaluations have been conducted on both synthetic and real world datasets. The experimental results verify the effectiveness and efficiency of our proposed methods. © 2018 IEEE.

Traffic data is used to estimate current traffic conditions so that travelers and agencies can make better decisions about how to use and manage the transportation network. This research explores the fusion of probe data (vehicle speed and direction) with loop data (density, speed, and count) in the context of producing overall network speed and travel time estimates. Speed and travel time estimates are useful in many circumstances, but current system control strategies (ramp metering, for example) require density data. While it is difficult to significantly increase the quantity of loop detectors on state highways, the penetration rate of probe data is continually increasing. Multiple data sources with various characteristics were fused by running probe and loop data through the Mobile Millennium highway model, generating velocity maps and travel times. The performance of data sources both individually and when fused was evaluated. It was found that the highest quality estimates are achieved by combining probe data and loop detector data.

[EN] In the road geometric design process, speed variation along the road segment is one of the most popular criteria to evaluate road consistency, hence the importance of estimating operating speed and its variations. Most of the estimation models are based on speed spot data collection, usually assuming some hypotheses like operating speed remains constant at curves and speed variations take place entirely at preceding tangent. This paper presents the results of the study of the deceleration phenomenon using a new methodology based on data collection by global positioning system devices. By means of this new methodology, not only new and more accurate models can be developed, but also the previous hypotheses can be checked and new studies can be carried out. Tangent-to-curve speed variations have been evaluated, comparing the 85th percentile speed differential (85V) and the differential of the 85th percentile operating speed (V85), analyzing the percentage of deceleration length that takes place at curves, and developing two deceleration models with radius of horizontal curve and parameter of transition curve as explanatory variables.

In this thesis the use of in-vehicle data, obtained from a uCAN, for the estimation of the traffic speed is investigated. Since vehicles are not equipped with a uCAN yet, the uCAN data is emulated. For this emulation, the traffic simulation model Fosim is used. With the emulated uCAN data, the minimum percentage of vehicles equipped with a uCAN that is necessary to accurately estimate the traffic speed is determined. This minimum percentage is equal to the minimum percentage for which the corresponding estimator for the traffic speed satisfies the accuracy requirement of NDW. The obtained percentage is applied to practical settings to generalize this result from a road section to the highway network of the Netherlands. Since the estimator for the traffic speed, based on data from inductive loop detectors, that is used nowadays does not satisfy the NDW requirement, the necessary minimum percentage of vehicles with a uCAN is also determined for two weaker requirements. The results based on these requirements are also generalized to the Dutch highway network. All three obtained necessary minimum percentages of vehicles with a uCAN for the three requirements also hold in the practical settings., Statistics, Applied mathematics, Electrical Engineering, Mathematics and Computer Science

The Virginia Center for Innovation and Transportation Research and Virginia Tech installed a structural health monitoring (SHM) system on a Virginia bridge. Using data from this SHM system as input, a procedure was developed to provide information on the lane occupancy, speed, classification and gross vehicle weight of heavy trucks. The resulting information is very useful for bridge management. The data also augments existing bridge WIM data collection sites in Virginia. The procedure could add functionality to other bridge SHM systems in Virginia. The system provides useful information on truck loading at low cost.

In the absence of intensive wind tunnel tests, this study provides an effective and accurate approach to estimate the operational driving speed limit on bridges subjected to different road conditions and wind intensities, through a convenient continuous simulation technique (CSP). A fast and vigorous simulation tool, vehicle performance simulation, is developed to effectively model the performance of vehicles traveling on bridges by considering the interactions between wind, vehicles, and the bridge. The CSP, on the other hand, dramatically reduces the data generation time and makes a reliability analysis of vehicles possible. The application of the proposed method on the Confederation Bridge in Canada is presented as a numerical example. The simulation result overrides the general impression that only high-sided vehicles are sensitive to wind attacks, and this work demonstrates that light-weighted vehicles are also likely to suffer from instability problems on bridges under relatively low wind velocity. In addition, different types of vehicle can undergo different instability mechanisms under the same wind condition and these vehicle instability mechanisms vary with wind velocity.

Traffic calming is more than just slowing down vehicles. It is thecombination of mainly physical measures that reduce the negativeeffects of motor vehicle use, alter driver behavior and improveconditions for non-motorized street use.

This report includes calendar years 1983 through 1989, and is the second speed survey made exclusively of rural interstate data. All data were retrieved from locations that have been exempted from the 55 MPH Speed Compliance Certification Program. The results of this study show that all vehicles on all Indiana rural interstate highways, had an average speed of 65.6 mph in 1989. This is 1.6 mph higher than the 1988 average speed of 64.0 mph, and 1.7 mph higher than the average speed of 63.9 mph during the 1987 calendar year. In addition, comparing Statewide speed versus vehicle length during 1989 indicates that the average speed of cars was 66.6 mph. This survey also shows that short trucks (21-45 feet) had an average speed of 64.4 mph, and long trucks (46-99 feet) had an average speed of 63.3 mph. The final Statewide results also indicate that 85 percent of all types of vehicles on all rural interstate highways are traveling at, or less than 73.9 mph. The charts, Figure 2 and Figure 3, graphically illustrate the speeds Statewide for all locations, and the percent greater than speed respectively. Table 5 summarizes an analysis of speed versus vehicle length Statewide during 1989, while Figure 5 graphically represents those results. Appendix A contains summarized statistics for each individual monitoring station from 1983 through 1989, while the Tables and Figures in Appendix B compare all stations. The Tables and Figures in Appendix C summarize the speed by length data at two stations that were used for comparing speed by length changes in 1989 from 1988. Summary Tables and Figures relative to speed versus length during 1989 can be found in Appendix D. Calculations for final Statewide statistics are located in Appendix E.

Dates inferred from the creation dates associated with the archival collection.

Pavement evaluation is critical for determining proper and cost-effective surface treatments and allocation of limited funds and resources to maintain, rehabilitate and reconstruct flexible pavements. This study examined two nondestructive testing devices that are used to evaluate the structural capacity and integrity of highway pavements including the Falling Weight Deflectometer (FWD) and Traffic Speed deflectometer (TSD). The researchers conducted a theoretical parametric study to simulate the FWD and TSD loading and predict pavement performance. In addition, they examined and analyzed FWD and TSD deflection data from various test sections in Idaho. Furthermore, they explored the use of Artificial Intelligence (AI) to predict pavement performance and layers’ moduli using the FWD and TSD deflection measurements. The results demonstrated that there was a good correlation between pavement mechanical responses (e.g., vertical compressive strain at top of subgrade and tensile strain at the bottom of asphalt layer) and FWD and TSD deflection parameters. Furthermore, the predicted pavement distresses had a good correlation with the deflection basin parameters. The analysis of FWD and TSD field deflection data demonstrated a strong correlation between FWD and TSD field deflections and effective structural number for the field sections. There was a good agreement between the assessment of pavement conditions using FWD and TSD for most of field sections. The AI was found to be a powerful technique to model pavement performance and response. Based on the comprehensive analysis conducted in this study, the TSD can be effectively used at the network level to identify hot spots or sections with potential structural deficiency for further FWD analysis at the project level. This can optimize the time and resources of employing the FWD crew and reduce traffic interruption and improve the safety of FWD crew and motorists.

69A3551747122, National Transportation Library (NTL) Curation Note: As this dataset is preserved in a repository outside U.S. DOT control, as allowed by the U.S. DOT’s Public Access Plan (https://doi.org/10.21949/1503647) Section 7.4.2 Data, the NTL staff has performed NO additional curation actions on this dataset. The current level of dataset documentation is the responsibility of the dataset creator. NTL staff last accessed this dataset at its repository URL on 2023-11-28. If, in the future, you have trouble accessing this dataset at the host repository, please email NTLDataCurator@dot.gov describing your problem. NTL staff will do its best to assist you at that time., The Town of Ennis reached out to the Western Transportation Institute (WTI) to determine options for ensuring that motorists followed the posted speed limit and yielded to pedestrians crossing Main Street/Highway 287. As a U.S. Highway, Main Street is under the jurisdiction of the Montana Department of Transportation (MDT). As such, researchers partnered with MDT to develop solutions for the portion of Highway 287 running through downtown Ennis., The total size of the zip file is 17.4 MB. The .csv, Comma Separated Value, file is a simple format that is designed for a database table and supported by many applications. The .csv file is often used for moving tabular data between two different computer programs, due to its open format. The most common software used to open .csv files are Microsoft Excel and RecordEditor, (for more information on .csv files and software, please visit https://www.file-extensions.org/csv-file-extension). The ECO file type is a proprietary file type that belongs to MetroCount Traffic Executive software. There is no open source alternative to this traffic software. Additionally, the researcher notes that there are 160 hours of raw video footage data not included in the data package. The researcher requests that if this raw footage is needed, contact them for this data.

As part of this study, 15 intersections with approximately 60 cameras were to be configured to collect traffic volumes and speeds. All of these cameras are the newer VISION models. In addition, the objectives of the study include building enhancements to the existing North Dakota State University (NDSU) Traffic Analysis Tool and to obtain cost estimates for upgrading East Grand Forks signalized intersections to enable similar data collection efforts within the metropolitan planning organization (MPO) region. This study was divided into six major tasks: Data Polling & Transfer, VISION Data Reporting, Data Quality Audits, East Grand Forks Estimation, Level of Service Estimation Feasibility Check, and Traffic Analysis Tool Enhancements.

SPR-4625, The adoption of dashboards and tools into Traffic Management Centers (TMC) has been growing with advancements in connected vehicle (CV) data. These tools are now being utilized—not only for analyzing work zones, severe crashes, winter operations, and traffic signals—but also to provide measures for characterizing overall system mobility, resiliency, and after-action assessments. Previous studies have extended the concepts to include the enhanced trajectory-based CV data into dashboards that aid agencies in assessing and managing roadways. This study presents the extension of these tools that further improve the value and insights provided. It also highlights the evolution of CV data in Indiana. CV data in Indiana has grown to over 364 billion statewide records. Average overall penetration rate of CV data on interstates has increased to 6.32% in May 2022 with trucks accounting for 1.7%. Sections of this study also present the impact of rain intensity on interstate traffic and incorporation of such weather data into heatmap and other tools. Updates to existing dashboards and a summary of newly developed dashboards are synopsized in this report. Finally, this report presents a case study that highlights the use of these tools to assess and analyze the impact of tornadoes on interstate traffic in Indiana. As interest in these tools has grown, this project facilitated continued improvements and added features to meet the needs of INDOT and their partners.

69A3551747122, The Town of Ennis reached out to the Western Transportation Institute (WTI) to determine options for ensuring that motorists followed the posted speed limit and yielded to pedestrians crossing Main Street/Highway 287. As a U.S. Highway, Main Street is under the jurisdiction of the Montana Department of Transportation (MDT). As such, researchers partnered with MDT to develop solutions for the portion of Highway 287 running through downtown Ennis.

MPC-519, Challenging roadway characteristics and high truck percentages create operational and safety concerns on I-80 in WY. High crash frequencies and delays are observed every year. WYDOT is looking for potential mitigation strategies to alleviate those problems. Researchers performed operational and safety analyses along I-80, with a focus on high truck percentages and climbing lanes as the most promising countermeasures for steep vertical grades. The operational analysis was performed through microsimulation and a creation of shock-wave based models, while the safety analysis included descriptive statistics, and cross-sectional and propensity-scores models to estimate the safety effectiveness of climbing lanes.

MPC-519, The State of Wyoming road network is characterized by heavy truck traffic. In 2015, truck traffic was approximately 22% of vehicle miles traveled (VMTs) along all routes in Wyoming, according to the WYDOT Annual Traffic Report. The heaviest truck traffic exists along I-80 with about 47% truck VMTs. Trucks have significantly different physical and driving characteristics than passenger cars, especially on grades, which has impacts on operational efficiency, safety, and pavement deterioration. The presence of heavy vehicles reduces the capacity of freeway segments, with the reduction being more significant along specific grades. This study focuses on the benefits of climbing lanes on operations and safety of freeway truck traffic. Various methodologies were used in this assessment. The results show that the addition of climbing lanes reduces delays and increases overall traffic speeds on upgrades, and can reduce the total and truck-related crashes from 6% to 34%, and from 1% to 16%, respectively, depending on the analyzed location and applied methodology.

DTFH61-83-C-00148, This research effort was conducted to determine the effectiveness of low-cost countermeasures in reducing the number of accidents at narrow bridges. The principal tasks consisted of 1) developing an accident based effectiveness evaluation plan and 2) conducting an operational based effectiveness evaluation. This report describes the activities and results of the operational based effectiveness evaluation. The operational based evaluation was performed by conducting before and after analyses of vehicle speed and lateral placement at 18 narrow bridge approach sites. The low-cost countermeasures that were evaluated consisted of combinations of advance warning signs, pavement markings, raised pavement markers, roadside delineators, type 3 object markers and adhesive delineators. The operational data were obtained by using the Federal Highway Administration's Traffic Evaluator System. With the exception of one analysis category, the operational based effectiveness evaluation did not reveal significant difference, at the 10 percent level, between the before and after time period. The one exception was that the low-cost countermeasures significantly reduced speed variation when all vehicle types and time periods were analyzed together. For this analysis category, therefore, the low-cost countermeasures resulted in more uniform driving behavior.

DTFH61-85-C-00172, The objective of this study was to develop an integrated survey vehicle for measuring pavement surface conditions at highway speeds. This was accomplished by determining the requirements and operating characteristics for such a system, preparing a design, and estimating initial and operating costs. This volume contains a review of the data and measurement needs for pavement condition surveys. The equipment available and under development for this purpose are identified with emphasis on measurements at highway speeds. Three potential survey vehicle designs are presented: the first uses off-the-shelf components, the second uses state-of-the-art components, while the third anticipates the addition of equipment still in development. The final design that was selected incorporates all three types of equipment. A complete, detailed design for the vehicle and the test equipment was prepared and each subpart discussed. Operating procedures for the survey vehicle are established and given in this report.

DTFH61-87-Z-00044, This report documents the design, development and validation of an upgraded pendulum for the Federal Outdoor Impact Laboratory (FOIL). The pendulum, which is designed to simulate the low-speed impact of a small automobile into breakaway luminaire and sign supports, has been upgraded with an 1800-lb (817 kg) mass, a new crushable nose design, special features to reduce pendulum harmonic ringing after impact, a new sweeper plate design, and provision for mounting on board accelerometers. Additional facility modifications developed as a part of this upgrade include a removable rigid foundation for mounting luminaire and sign supports and a new speed trap system. Testing conducted on the new pendulum system confirmed the adequate operation of the new speed trap system and the acceptability of the removable rigid foundation. In addition, the pendulum crush characteristics were shown to be in agreement with the crush characteristics of the bogie vehicle put into service in 1985, and to closely model the crush of the automobile which was used as a basis for the pendulum development. Tests with the new sweeper plate design confirmed its proper performance, though the breakaway force level was 50% higher than the design value. Tests with actual luminaire supports demonstrated that the pendulum could indeed be used to simulate the low-speed impact of a small car into sign and luminaire supports, though there were anomalies in the data from the slip base testing. The new speed trap system and the new sweeper plate were recommended for implementation at the pendulum facility, though the attachment bolts of the sweeper plate should be replaced with lower strength bolts so that the breakaway force level is reduced. The pendulum was recommended for evaluation of anchor base, transformer base, progressive shear, coupling mounted and other breakaway luminaire and sign supports which have already been shown to perform satisfactorily with the bogie vehicle. However, further research w

This study sought to identify best practices for setting work zone speed limits by state departments of transportation (DOTs) and to evaluate select strategies for improving compliance with work zone speed limits. The objectives of this project were achieved by synthesizing information from a literature review, a state DOT survey, and field evaluations of select speed management strategies.

UC-ITS-2019-11, This project combined the statewide crash data (SWIRTS) and traffic data (PeMS) to develop statistical models to determine the safety impacts of alternative speed limits on California highways. The models examined whether various factors about crashes, including average traffic speed and truck-involvement, correlated with outcomes such as crash severity. The models were then used to test the impact of four alternative speed limit policies (B-E) on the predicted number of fatal crashes and unsafe-speed related crashes in urban and rural areas. The policies were: (A) Existing differential speed policy for cars (65 mph) and trucks (55 mph); (B) Raising the speed limit on interstates for trucks from 55 to 65 mph; (C) Raising the speed limit on interstates from 55 to 75 mph for trucks and 65 to 75 mph for cars; (D) Lowering the existing differential speed on interstates from 55 to 50 mph for trucks and 65 to 60 mph for cars; (E) Raising the existing differential speed on interstates from 55 to 70 mph for trucks and 65 to 80 mph for cars. The policy analysis shows a difference in the predicted number of crashes (fatal, unsafe speed) in and between urban and rural areas. The percentage increase/decrease in predicted fatal crashes in rural areas is lower than urban areas across all policy alternatives.

69A3551747111, National Transportation Library (NTL) Curation Note: As this dataset is preserved in a repository outside U.S. DOT control, as allowed by the U.S. DOT's Public Access Plan (https://doi.org/10.21949/1503647) Section 7.4.2 Data, the NTL staff has performed NO additional curation actions on this dataset. The current level of dataset documentation is the responsibility of the dataset creator. NTL staff last accessed this dataset at its repository URL on 2022-11-11. If, in the future, you have trouble accessing this dataset at the host repository, please email NTLDataCurator@dot.gov describing your problem. NTL staff will do its best to assist you at that time., Complete streets facilitate multi-modal travel through human-centric infrastructure design with goals of improving safety and accessibility for all potential travelers. Examples include designing corridors with wide sidewalks, lighting, street furniture, adding bike lanes, improving transit shelters and turnouts, among others. This study evaluates the travel impacts resulting from a complete street redesign project through an urban corridor in Pittsburgh, Pennsylvania. The retrofit project involved reducing vehicle lanes from four (two lanes in each direction) to three (one lane in each direction with a center turn lane) and adding dedicated bike lanes in each direction. The project also included new traffic signals, one new pedestrian crossing, reconfiguration and relocation of several intersections, improved bus turnouts, new pavement, and new street furniture. Before-and-after travel impacts (traffic counts and speeds, transit ridership, bicycle counts, air quality, and crash counts) were evaluated to quantify total benefits resulting from the retrofit project. The total size of the described csv file is 4.30 MB. The .csv, Comma Separated Value, file is a simple format that is designed for a database table and supported by many applications. The .csv file is often used for moving tabular data between two different computer programs, due to its open format. Any text editor or spreadsheet program will open .csv files.

The Vermont Agency of Transportation (VTrans) undertook a major repaving/reconstruction project over a six-mile segment of northbound lanes of Interstate 89 (I-89) in the summer of 2008. In this study, VTrans contracted with the Transportation Research Center at the University of Vermont (UVM) to use a UVM developed regional microscopic traffic simulation model to evaluate the impacts of the various work zone traffic control strategies. In this report the authors present a traffic impact analysis of the work zone on interstate I-89 modeled using a PARAMICS based micro-simulation model. Additionally, the authors analyze the traffic characteristics (traffic counts and speed) observed during construction and compare it with the before-construction and model predicted traffic characteristics.

Connected and automated vehicle (CAV) driving features can impact traffic safety in many aspects owing to their improved driving behavior. On the other hand, road geometric design elements are mainly based on human reactions and behavior, which might affect safety depending on road layout and the parties involved. However, automation and connectivity can convey more data about the driving environment that will reduce confronting unexpected driving conditions and driving load on drivers. Therefore, the risk of crashes due to roadway geometries will be reduced. The main objective of this study is to focus on the performance of the traffic flow, including CAVs with different geometric designs addressing the potential crash spots. This study aims to determine the efficacy of CAVs on traffic network safety quantitively and qualitatively. For this purpose, multiple scenarios with different geometric features are designed and simulated. Simulations include varied CAV shares in traffic composition and employ driving features of CAVs. Using the surrogate safety assessment model (SSAM), simulation results are evaluated for potential conflicts. Crash severity, frequency, and classification are studied to determine the safety effects of CAVs on potential crash hot spots. Results indicated that higher penetration rates of CAVs could improve the safety performance of traffic networks in multiple cases by reducing deceleration rates, cooperative lane changing, and adjusted speed in required situations. However, due to the interaction of CAVs and HDVs in a signalized intersection, safety performance might not benefit from CAV presence.

It is expected that compared to conventional vehicles, CAV can upgrade flow capacity, travel time, and, most importantly, the safety of traffic roads. Road elements that can impact drivers’ performance include the number of lanes, lane width, design speed, curves, road slope.

The cost of fuel represents a major portion of the costs of operating on-road heavy-duty vehicles (HDV). According to the American Transportation Research Institute, fuel costs alone amounted to about 25 percent of truck operating costs in 2015. Within the U.S. on-road transportation sector HDVs consume a disproportionately high amount of the total refined petroleum-based fuel and carbon dioxide emissions from consumption of this fuel were estimated to be equivalent to over 400 million metric tons. HDVs also contributed a disproportionately high 2.5 million short tons of Oxides of Nitrogen (NOx) emissions, emitted as a by-product of fuel combustion in on-road vehicle engines. NOx is a precursor of ozone, which is an air pollutant harmful to humans, plants, and animals. Over the next couple of decades, the total energy demand from the HDV sector will likely increase due to forecasted growth in freight demand in many global markets, including the United States, and much of this energy will continue to be provided by fossil fuels. Therefore, carbon dioxide emissions from the HDV sector are also expected to increase in the absence of effective mitigating measures to reduce the sectors reliance on fossil fuels. In this study, the authors develop a tool to predict the fleet-wide fuel-saving benefits from low rolling resistance tires. Unlike previous studies, the developed tool is applicable to both stabilized speed operations and transient speed operations. The tool is based on empirical models that estimate the fuel consumption contribution from tires as a function of vehicle payload, aerodynamic drag, road grade, duration of acceleration, duration of deceleration and, and road facility type (freeway, major arterial, and minor arterial/local road). The authors limited the scope of the developed tool to tractor-trailers in the U.S. heavy-duty vehicle market, because the United States has the second largest HDV market in the world and tractor-trailers account for the large

69A3551747133, The goal of this project is to improve mobility in urban street networks by developing a methodology for dynamic speed harmonization suitable for connected urban street networks. The methodology aims at finding optimal advisory speeds on each transportation link that will be transferred to connected and autonomous vehicles, with the objective of reducing travel time, improving mobility, and harmonizing the speeds at the same time. As such, the methodology can avoid long queues, queue spillovers, and gridlocks. This study will generate the first network-level formulation for dynamic speed harmonization in a signalized network. It will also incorporate connected vehicle information in the mathematical model and the proposed solution algorithm. The objective of this research is to study the effects of harmonizing the speed of connected automated vehicles on traffic operations in urban street networks. In particular, this study proposes the use of optimal speed control methods to develop an efficient optimization framework for an effective and fluent movement of connected automated vehicles (CAVs) in urban street networks. This study aimed at finding answers to the following fundamental research questions: (1) What is the effect of speed control on the operational performance of connected urban street networks? (2) How cooperative optimization of signal timing plans and speed of CAVs further improves the performance of transportation networks?

SPR-P1(06) P582, Until recently, guidelines for the geometric design of acceleration lanes used for the, successful merge of an entering vehicle into a high-speed surface transportation system, through-traffic lane have been based upon concepts and vehicle characteristics from the, 1930s. Modern changes in vehicle characteristics and an increase in the percentage of large, trucks using the roadway systems has necessitated reviewing the dated guidelines to, determine if they are still suitable and if not, make recommendations for modifications., Consistency of use of the current guidelines has no doubt shaped driver behaviors over, the years to promote expectations for desirable design features that encourage successful, merging outcomes. This report summarizes the history of the geometric features of, acceleration lanes, compares the outcome of recent merge-lane research studies, discusses, prevalent driver behavior patterns from field studies and recommends the use of tapered and, parallel type lanes in specific situations., Overall, the current AASHTO guidelines provide adequate acceleration lane length, guidance values for all vehicles except heavy trucks. If a large percentage of heavy trucks are, expected to use a particular merging lane, general planning guidelines are listed to, accommodate their accelerating characteristics and provide adequate distance for an, appropriate entering speed into the adjacent through traffic lane.

DTRT06-G-0044, Agencies in the Houston region have traditionally used toll tag readers to provide travel times on, freeways and High Occupancy Vehicle (HOV) lanes, but these systems require large amounts of costly and, physically invasive infrastructure. Bluetooth is a widely used technology embedded in cellular telephones and, in-vehicle applications for exchanging data over short distances. The initial demonstrations of wireless, address matching were primarily designed to prove the ability for Bluetooth technology to produce matches, between two points on a roadway outfitted with the proper Bluetooth reader equipment, with a resulting travel, time and speed calculated. Costs for Bluetooth travel time measurement systems are one to two orders of, magnitude below costs for traditional toll tag reader equipment, depending on the application. This cost, advantage could significantly lower the threshold for hundreds of agencies and private entities to enter the, travel time measurement market, but there is little guidance on the application. Development and testing of, various prototype software and hardware platforms were conducted to use the anonymous Media Access, Control (MAC) address from each Bluetooth device to measure and report real-time traffic conditions., Several issues were examined and resolved in order to develop a true first generation “product.” The, development of this method and process is pending patent approval., 17. Key

SPR 304 - 161, The combination of increased demands on Oregon’s transportation system and limited law enforcement resources has led the Oregon Department of Transportation (ODOT) to investigate whether a relationship exists between motorists’ speeds and law enforcement levels. If an optimum level of law enforcement could be identified that reduces the number of motorists driving in an unsafe manner, the end result could be a more efficient deployment of scarce law enforcement resources., This study deployed enhanced law enforcement patrols at six study sites in Oregon to evaluate the effects of law enforcement presence on vehicle speeds. Investigators first recorded baseline speeds for a two-month period prior to the commencement of enhanced enforcement. Enhanced patrols varied from 10 to 25 hours per week on either fixed or random schedules. Enforcement at each site was on an eight-week cycle: two weeks of enhanced patrols followed by six weeks of normal patrols., The data analysis compared median and 85th percentile speeds in the baseline and enhanced enforcement conditions. Baseline and enhanced enforcement data were also compared for the percent of vehicles traveling over the posted speed at each site. The findings showed that enhanced patrols resulted in small but statistically significant reductions in speed at most of the test sites. Both median and 85th percentile speeds were significantly higher than posted speeds at all of the study sites in both the baseline and the enhanced enforcement conditions.