As freight transportation volumes have grown rapidly—further spurred by pandemic-driven e-commerce growth—state departments of transportation (DOTs) have become increasingly reliant on probe data to monitor freight infrastructure performance, manage demand, and understand freight infrastructure needs. NCHRP Synthesis 611: Use of Probe Data for Freight Planning and Operations , from TRB's National Cooperative Highway Research Program, documents current state DOT practices regarding the use of probe data i...

Road tunnels employ a multitude of functional systems that include a variety of equipment: lighting, ventilation, power supply, fire protection systems such as fixed fire-fighting systems, fire detection systems, communications systems and operational devices, supervisory control and data acquisition, closed circuit television, variable message signs, and radio. Maintenance of these systems is critical to the operation of the tunnel and to the overall roadway network. NCHRP Synthesis 607: Critical Findin...

In comparable private sectors, incentive and disincentive programs have effectively promoted safe behaviors by employees. However, state departments of transportation (DOTs) have unique limitations and restrictions on their ability to financially incentivize safe actions by highway construction and maintenance crews or, in some cases, implement corrective actions to disincentivize unsafe actions. While navigating these restrictions is difficult, some DOTs have implemented unique approaches in order to in...

Most state departments of transportation (DOTs) use social media to broadcast information and monitor emergencies, but few rely heavily on social media data. The most common barriers to using social media for emergencies are personnel availability and training, privacy issues, and data reliability. NCHRP Synthesis 610: Leveraging Social Media Data for Emergency Preparedness and Response , from TRB's National Cooperative Highway Research Program, documents state DOT practices that leverage social media da...

Most state departments of transportation (DOTs) are aware of the importance of integrating freight and active transportation, but there is a lack of coordination and standardized protocols for doing so. NCHRP Synthesis 606: Integrating Freight and Active Transportation into Policies, Programs, Plans, and Project Development , from TRB's National Cooperative Highway Research Program, documents state DOT practices, tools, and approaches related to the integration of freight and active transportation policy...

State departments of transportation (DOTs) are facing the challenge of maintaining and preserving local environmental systems while meeting transportation needs. Stormwater best management practices (BMPs) can help mitigate ecological impacts, and unmanned aerial systems (UAS) can be used to track, monitor, and document BMPs throughout their life cycle. NCHRP Synthesis 609: Use of Unmanned Aerial Systems for Inspection of Stormwater Best Management Practices , from TRB's National Cooperative Highway Rese...

State departments of transportation (DOTs) are working to deploy electric vehicle (EV) charging infrastructure, but face challenges and need AASHTO-type guidelines to help with deployment. NCHRP Synthesis 605: Electric Vehicle Charging: Strategies and Programs , from TRB's National Cooperative Highway Research Program, documents current strategies and practices in use by state DOTs to facilitate and coordinate the provision and operation of EV charging facilities. The synthesis also includes DOTs’ curren...

There are a variety of ways to achieve tolerances in steel bridge fabrication and erection. One common method is to use shop assembly, which is the process of assembling steel members in the shop before they are erected on site. Another method is to use oversize holes, which are holes that are slightly larger than the required size. NCHRP Synthesis 603: Practices for Steel Bridge Fabrication and Erection Tolerances , from TRB's National Cooperative Highway Research Program, details the use of tolerances,...

Many bridges are built without accommodations for active transportation users and only serve motorized traffic. The pedestrians and bicyclists who rely on these bridges are exposed to safety-related concerns and their access to equal employment opportunities and essential services may be hindered. The TRB National Cooperative Highway Research Program's NCHRP Synthesis 604: Practices for Adding Bicycle and Pedestrian Access on Existing Vehicle Bridges documents the practices employed by state departments ...

The increased frequency of extreme rainfall events, inland and coastal flooding, and other water-related stressors poses challenges to roadway infrastructure. The TRB National Cooperative Highway Research Program's NCHRP Synthesis 602: Resilient Design with Distributed Rainfall-Runoff Modeling documents the practices of state departments of transportation on the use of DRRMs and identifies state DOTs that have adopted DRRMs and the context in which these models are applied.