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To combat expensive bridge deterioration caused by corrosion, this project investigated the feasibility of using dissimilar metal welds (DMWs) to protect highly corrosive locations while minimizing initial fabrication costs. The research evaluated welding corrosion-resistant steels—specifically ASTM A709 Grade 50CR and a potential alternative, ATI 412—to standard structural bridge steels (ASTM A36 and ASTM A709 Grade 50W). Initial weldability evaluations indicated that these DMWs are highly susceptible to solidification and cold cracking. However, researchers determined that utilizing lower heat input and a single-V with backgouge weld joint successfully eliminated these defects, allowing the crack-free DMWs to ultimately meet the mechanical property requirements of the AASHTO/AWS D1.5 Bridge Welding Code.

Despite satisfying basic mechanical standards, the DMWs exhibited severe vulnerabilities during corrosion and non-destructive evaluation (NDE) testing. The material combinations suffered from accelerated galvanic, pitting, and intergranular corrosion, particularly within the heat-affected zones of the weld interfaces. Furthermore, standard NDE inspection methods proved highly unreliable; radiographic testing produced artifacts that could mask flaws, while ultrasonic and phased array testing suffered from anisotropic behavior and wave refraction that caused defects to be mislocated or missed entirely. Consequently, because of these persistent corrosion and inspection challenges—compounded by long lead times and recent quality issues with 50CR steel—the Virginia Transportation Research Council recommends that VDOT avoid utilizing 50CR/412 steel in DMWs and continue to exercise caution when specifying 50CR steel to manage project risk.

This research evaluated the effectiveness of nighttime construction lighting systems in improving worker visibility and safety while minimizing glare impacts on motorists in Nebraska work zones. The study combined an industry survey with controlled field testing to assess current lighting practices and quantify lighting performance. Survey responses from construction professionals documented commonly used lighting systems, perceived adequacy, safety impacts, and public concerns related to glare. Field experiments were conducted at the Midwest Roadside Safety Facility using LED, halogen, and balloon light towers. Lighting configurations were systematically varied by mounting height, aiming angle, and rotation angle. Worker visibility was evaluated using horizontal illuminance based on Federal Highway Administration recommendations, and driver glare was assessed using veiling luminance ratios in accordance with Illuminating Engineering Society RP-8-22 standards. Results indicate that lighting performance depends primarily on configuration rather than lighting type alone, and only a limited number of configurations satisfied both illuminance and glare criteria. The findings can be used to guide safer nighttime work zone lighting setup and support the development of NDOT-specific lighting recommendations.

This study highlights that Inductive Loop Detectors (ILDs), sensors embedded into the pavement for traffic control, are concerningly vulnerable to novel cyber and physical attacks.

Probe data are increasingly being adopted by transportation professionals in the United States as a means to better measure the mobility of Americans across and within the national transportation system. Centered on new, rapidly changing forms of technology that allow mobile devices to actively determine and share their locations with analysts as a novel form of big data, probe data offer exciting advantages for measuring mobility, but they rely on technologies and methods that are not transparent to their users or members of the public. This report offers a statistics-centered definition of probe data, contrasts them with non-probe data, notes common data subtypes, discusses their advantages and limitations, summarizes their history, and proposes ways to differentiate noted subtypes. This report accompanies a set of six user guides on specific probe data types.

Federal agencies increasingly use cloud computing to perform their missions. Cloud services provide benefits, including on-demand access to shared resources such as networks, servers, and data storage, and can enable agencies to deliver IT services more efficiently. Additionally, cloud services can provide agencies with opportunities to obtain IT capabilities more quickly and potentially at a lower cost than building and maintaining their own computing infrastructure. In pursuing these benefits, agencies may also encounter various risks and challenges, such as managing shared cybersecurity responsibilities with the provider.

This review determined the extent to which selected agencies are ensuring contractor compliance with key cloud computing security practices. To address the objective, researchers identified a non-generalizable sample of four Chief Financial Officers Act agencies based on the number of cloud authorizations issued, excluding agencies selected in recent GAO reports. Using the median number of authorizations, agencies were randomly selected with two at or above, and two below the median: Departments of State, Transportation, Veterans Affairs (VA), and the Small Business Administration (SBA).

Several state departments of transportation have integrated mobile road weather information sensors (RWIS) and maintenance decision support systems (MDSS) to improve the performance of their winter maintenance operations. The main goal of this research project is to conduct a multi-year field study to evaluate the effectiveness of integrating mobile RWIS and MDSS into existing Illinois Department of Transportation (IDOT) winter maintenance operations. The project focused on eight research tasks. Tasks 1 through 3 comprised identifying IDOT study participants for the deployment of mobile RWIS units and MDSS; selecting, acquiring, installing, calibrating, and providing training on 12 mobile RWIS units acquired from three manufacturers; and conducting a multi-year field evaluation of mobile RWIS units and MDSS during three consecutive winter seasons to assess their operational performance and effectiveness. Salt usage data were collected and analyzed in Task 4 through pairwise comparisons of snowplows with and without mobile RWIS units and MDSS to evaluate their effectiveness in reducing salt usage and improving roadway conditions. Surveys and follow-up interviews with winter maintenance personnel were conducted in Task 5 to gather and analyze feedback on the use, benefits, and operational challenges of mobile RWIS units and MDSS. Tasks 6 through 8 comprised evaluating the cost-effectiveness of the three mobile RWIS models and MDSS, identifying additional uses for mobile RWIS units, and developing recommendations for future deployment and use of mobile RWIS units and MDSS across Illinois.

The permitting process for electric vehicle supply equipment (EVSE) varies significantly across authorities having jurisdiction (AHJs), who regulate localities spanning urban to rural spaces. This variance, which manifests in multiple components of the process including the steps to obtain a permit, the code requirements, and the type of permit or reviews required (i.e., electrical, building, zoning), can lead to uncertainty surrounding EVSE project requirements and time delays in both the development and review of project plans. Ultimately, these delays add time and cost to the projects and are a commonly noted barrier to successful EVSE installation (Gilliand and Graff 2023; Nelder and Rogers 2019; O’Grady and Way 2019).

The Stations Tool for Automated Permitting (S-TAP) is a spreadsheet-based tool designed to validate nonresidential EVSE projects against code requirements and reduce the time required for AHJs (i.e., the permitting authority) to issue the permit. The tool consists of a questionnaire that evaluates project inputs based on widely adopted model codes (National Electric Code and International Building Code) and select local regulations, through a series of validation logic. The consistent evaluation of project specifications based on set model codes standards within the tool, with some elements that are designed for AHJ-specific inputs, provides the effect of streamlining the codes that define the EVSE project design and installation. The goal of the tool is to reduce the time required during the permitting process for the AHJ staff to review the plan and evaluate the EVSE project for code compliance, specifically for high-frequency and low complexity projects, thereby allowing AHJ staff to focus time and attention on higher complexity projects.

This user manual provides an overview of S-TAP, including the methodology leveraged to develop the tool, technical guidance on how to use the tool, and the purpose or use case for this tool with different audiences.

This fact sheet, sponsored by Desjardins Insurance, examines the magnitude of and trends in collisions involving driver distraction in motor vehicle fatalities in Canada from 2000 to 2023, using data from TIRF’s National Fatality Database (TIRF, 2026). Fatalities included in this analysis are persons who died within 30 days of a collision which occurred on a public roadway and at least one of the vehicles involved was a principal highway vehicle (i.e., automobile, van, truck, motorcycle, bus). Topics explored in this fact sheet include the role of driver distraction among road deaths, the characteristics of distracted drivers and pedestrians killed in collisions, and characteristics of distraction-related fatal collisions, including temporal factors, vehicle type, occupants, and geographic location.

This study evaluated the effects of R1-6a pedestrian crossing signs, installed in various configurations, on driver yielding behavior at uncontrolled marked crosswalks across six Oregon locations. The research analyzed both staged and naturalistic crossings under different experimental conditions, including baseline, tubular markers, single and multiple R1-6a signs, and gateway installations. Video data were coded to assess crossing volumes and yielding rates for over 5,900 pedestrians. Baseline yielding was already high, averaging 85% nearside and 89% farside, but increased further with sign treatments. The gateway configuration achieved the highest yielding rates of 92% (nearside) and 97% (farside), while curb-top edge sign placement produced 87% nearside yielding and 99% farside yielding. These findings demonstrate that R1-6a signs, particularly in gateway configurations, enhance driver yielding even when baseline compliance is high, though variations across sites highlight the influence of differing roadway contexts and pedestrian environments.

This fact sheet, sponsored by Desjardins Insurance, examines the magnitude of and trends in collisions involving driver speed in motor vehicle fatalities in Canada from 2000 to 2023 using data from TIRF’s National Fatality Database (TIRF, 2026). Fatalities included in this analysis occurred on public roadways with persons dying within 30 days of the collision and at least one of the vehicles involved was a principal highway vehicle (i.e., automobile, van, truck, motorcycle, bus). Topics explored in this fact sheet include the role of driver speed in road deaths, characteristics of speeding drivers killed in collisions, and characteristics of speed-related collisions resulting in fatalities, including temporal factors, vehicle type, occupants and geographic location.

For more than a decade, the AAA Foundation for Traffic Safety (AAAFTS) has measured Americans’ traffic safety culture through its annual Traffic Safety Culture Index (TSCI) survey. The TSCI evaluates five key dimensions: how dangerous drivers perceive risky driving behaviors to be, how likely they believe they are to be apprehended for engaging in risky driving behaviors, how much social disapproval they associate with risky driving behaviors, how frequently they report engaging in risky driving behaviors themselves, and their support for safety laws related to risky driving behaviors. The 2025 TSCI builds upon this established framework by incorporating additional measures related to contextual and personal influences on driving behavior. First, this survey examines drivers’ perceptions of both safe and risky driving behaviors in their own neighborhoods. Such perceived neighborhood driving behaviors may shape individuals’ own driving behavioral choices, as prior research suggests that drivers tend to follow and imitate the behaviors of those around them (Mohammadi et al., 2021; Zhang et al., 2025). Second, the survey explores self-appraisals of behavior and abilities, which may be systematically biased by the “better-than-average effect,” a well-documented tendency for drivers to rate their own skills and behaviors more favorably than those of their peers (Horswill et al., 2004; Horswill et al., 2013). This bias is frequently associated with overconfidence and an increased likelihood of engaging in risky driving behaviors (Măirean & Havârneanu, 2018; Horrey et al., 2015). Third, this survey explores drivers’ social stress. Previous research has indicated that elevated social stress levels can contribute to increased distraction, aggression, and impairment behind the wheel (Suhr & Dula, 2017). These additional measures provide a more comprehensive picture of the factors influencing risky driving behaviors.

The tables in this document summarize the U.S. motorcycle population between 2002 (the earliest available year of data) and 2026, based on Institute analyses of data provided by S&P Global Mobility. Registration counts as of January 1 of each year were provided by year, state, and Vehicle Identification Number (VIN) pattern (first 10 digits). Software developed and maintained by the Highway Loss Data Institute (HLDI) was used to decode VIN patterns to determine make, series, and model year, and to append information maintained by HLDI on motorcycle type and antilock braking system (ABS) availability. Only on-road classes of motorcycles were included. Since the VIN information is constantly improving, counts in this paper may differ slightly from the previous versions.